SECTION 3B1 - ELECTRICAL POWER

STEERING (P/S) SYSTEM

1. GENERAL DESCRIPTION

1.1 SYSTEM COMPONENTS

2. WIRING DIAGRAM

3. DIAGNOSIS

3.1 ON-BOARD DIAGNOSTIC SYSTEM

3.2 PRECAUTIONS IN DIAGNOSING

TROUBLES

3.3 SYSTEM CHECK FLOW TABLE

Customer Questionnaire Example

3.4 EPS WARNING LAMP CHECK

3.5 DTC CHECK

Using Tech 2

Not Using Tech 2

3.6 DTC CLEARANCE

Using Tech 2

Not Using Tech 2

3.7 SERIAL DATA LINK CIRCUIT CHECK

Diagnostic Flow Table

3.8 DTC TABLE

3.9 TABLE A - EPS WARNING LAMP DOES

NOT ILLUMINATE WITH IGNITION

SWITCH ON AND WITH ENGINE NOT

RUNNING

Circuit

Inspection

3.10 TABLE B - EPS WARNING LAMP

FLASHES WITH IGNITION SWITCH ON

Circuit

3.11 TABLE C - EPS WARNING LAMP DOES

NOT FLASH, REMAINS ON OR OFF,

EVEN WITH DIAGNOSIS SWITCH

TERMINAL GROUNDED

Circuit

3.12 DTC C1111 (DTC No.11) TORQUE

SENSOR MAIN CIRCUIT FAILURE

3.13 DTC C1113 (DTC No.13) TORQUE

SENSOR MAIN AND SUB CIRCUIT

FAILURE

3.14 DTC C1115 (DTC No.15) TORQUE

SENSOR SUB CIRCUIT FAILURE

3.15 DTC C1114 (DTC No.14) TORQUE

SENSOR 5V POWER SUPPLY CIRCUIT

FAILURE

3.16 DTC C1116 (DTC No.16) TORQUE

SENSOR 8V POWER SUPPLY CIRCUIT

FAILURE

3.17 DTC C1121/C1123/C1124

(DTC No.21/23/24) VSS CIRCUIT

FAILURE

3.18 DTC C1122 (DTC No.22) ENGINE SPEED

SIGNAL CIRCUIT FAILURE

3.19 DTC C1141/C1142/C1143/C1144/C1145

(DTC No.41/42/43/44/45) MOTOR

CIRCUIT FAILURE

3.20 DTC C1151 (DTC No.51) CLUTCH

CIRCUIT FAILURE

3.21 DTC C1153(DTC No.53) P/S CONTROL

MODULE POWER SUPPLY CIRCUIT

FAILURE

WARNING:

For vehicles equipped with Supplemental Restraint (Airbag) System:

• Service on and around the airbag system components or wiring must be performed only by an

authorised HOLDEN retailer. Refer to AIRBAG SYSTEM COMPONENTS AND WIRING LOCATION

VIEW under GENERAL DESCRIPTION in Section 10B AIRBAG SYSTEM in order to confirm

whether you are performing service on or near the airbag system components or wiring. Please

observe all WARNINGS and SERVICE PRECAUTIONS under ON-VEHICLE SERVICE in Section

10B AIRBAG SYSTEM before performing service on or around the airbag system components or

wiring. Failure to follow WARNINGS could result in unintentional activation of th e system or could

render the system inoperative. Either of these two conditions may result in severe injury.

• Technical service work must be started at least 90 seconds after the ignition switch is turned to

the “LOCK” position and the negative cable is disconnected from the battery. Otherwise, the sys-

tem may be activated by reserve energy in the Sensing and Diagnostic Module (SDM).

IMPORTANT:

Prior to connecting Tech 2 to the vehicle, ref e r to Section 0C TECH 2.

3.22 DTC C1152/C1154/C1155 (DTC No.52/54/

55) P/S CONTROL MODULE FAILURE

3.23 TROUBLE DIAGNOSIS (FOR TROUBLE

NOT INDICATED BY ON-BOARD

DIAGNOSTIC SYSTEM)

3.24 INSPECTION OF THE P/S CONTRO L

MODULE AND ITS CIRCUITS

Voltage Check

3.25 STEERING WHEEL PLAY INSPECTION

3.26 STEERING FORCE INSPECTION

4. ON-VEHICLE SERVICE

4.1 STEERING COLUMN ASSEMBLY

Removal

4.2 CHECKING STEERING COLUMN

ASSEMBLY AND LOWER SHAFT FOR

ACCIDENT DAMAGE

Checking Procedure

4.3 P/S CONTROL MODULE

Removal

Installation

4.4 TORQUE SENSOR

On-Vehicle Inspection

4.5 MOTOR ASSEMBLY (WITH CLUTCH

INCORPORATED)

On-Vehicle Inspection

5. SPECIAL TOOLS

1. GENERAL DESCRIPTION

1.1 SYSTEM COMPONENTS

The electrical power steering (P/S) system consists of a P/S control module, a torque sensor and a motor and

clutch installed to the steering column.

The P/S control module determines the level and direction of the assist force for the steering wheel according

to the sig nals from the torqu e sensor and the vehic le speed and then oper ates the moto r to assis t the opera-

tion of the steering wheel.

When the ignition switch is ON and the engine is running, the P/S control module diagnoses faults which may

occur in the following components:

• Torque sensor

• Vehicle speed sensor (VSS) circuit

• Engine speed signal circuit

• Motor

•Clutch

• P/S control module

When P/S control module detects a malfunction, it stops the motor and clutch control.

Legend

1. Steering wheel 4. Torque sensor 7. Battery

2. Steering column assembly 5. Motor and clutch 8. VSS

3. P/S control module 6. Steering gear box 9. ECM

2. WIRING DIAGRAM

Legend

YGM3B131

1. Main fuse box 10. To immobiliser control module 19. Ground terminal

2. Circuit fuse box 11. To circuit fuse box 20. P/S control module

3. P/S fuse (30A) 12. Data link connector (DLC) 21. Motor assembly

(with clutch incorporated)

4. IG fuse (15A) 13. Ground on body

5. Ignition switch 14. Ground on engine block 22. Torque sensor

6. Combination meter 15. To ECM, air bag SDM and 22. Torque sensor

7. Speed meter ABS hydraulic unit/control 23. Connector G24

8. EPS warning lamp module assembly (viewed from harness side)

9. To vehicle speed sensor 16. To ECM 24. Connector G24-2

(VSS) 17. Diagnosis connector No. 2 (viewed from harness side)

18. Diagnosis switch terminal 25. Connector G24-1

(for P/S system) (viewed from harness side)

3. DIAGNOSIS

The P/S system is controlled by the P/S co ntrol module which has an on-board diagnostic system to detect

malfunctions in the system.

When diagnosing faults, be sure to have a full understanding of the outline of 3.1 ON-BOARD

DIAGNOSTIC SYSTEM and each item in 3.2 PRECAUTION IN DIAGNOSING TROUBLES and execute

diagnos is, refer to 3.3 SYSTEM CHECK FLOW TABLE in this Section.

3.1 ON-BOARD DIAGNOSTIC SYSTEM

The P /S con t rol mo dul e pe rfo rms o n- boa rd d ia gnos is ( self-

diagnos is) on the s ystem and op erates EPS warning lamp

(1) (malfunction indicator lamp) as follows:

• Malfunction indicator lamp (EPS warning lamp) lights

when the ignition switch is turned to ON position (but

with the engine not running) regardless of the condition

of the P/S control system. This is only to check the

malfunction indicator lamp (EPS warning lamp) bulb

and its circuit.

• If the areas monitored by the P/S control module are

free from any faults after the engine starts (while

engine is running), the malfunction indicator lamp (EPS

warning lamp) turns OFF.

• When the P/S con tr ol mod ule detec ts a fault which has

occurred in the areas it monitors, the malfu nction indi-

cator lamp (EPS warning lamp) turns ON while the

engine is running to warn the driver of such occurrence

of trouble and at the same time it stores the exact trou-

ble area in memory inside the P/S control module.

3.2 PRECAUTIONS IN DIAGNOSING TROUBLES

• Take a note of DTC indicated first.

• Before inspection, refer to Section 0A PRECAUTIONS FOR ELECTRICAL CIRCUIT SERVICE.

• When tw o or mor e trou ble s ha ve occ urr ed, their DTCs ar e in dicated 3 times eac h, s tarting with the s mal l-

est code number.

• DTC C1122 (DTC No.22) (engine speed signal failure) is indicated when the ignition switch is in the ON

position and the engine is not running but if the indication changes to normal when the engine is started, it

means there is nothing abnormal.

• As DTCs are stored in the memory of the P/S control module, be sure to clear the memory after any

repairs by performing the DTC clearance procedure, refer to 3.6 DTC CLEARANCE in this Section.

3.3 SYSTEM CHECK FLOW TABLE

WARNING: Carry out test in a low traffic area to prevent an accident.

Step Action Yes No

1. 1. Record details of the problem (failure, complaint) and how it

occurred as described by the customer.

For this purpo se, use of a questionai re form as shown bel ow

will facilitate collecting information to the point required for

proper analysis and diagnosis.

2. Check if what the customer claimed in the CUSTOMER

QUESTIONAIRE is actually found in the vehicle and if that

symptom is found, whether it is identified as a failure.

(This step should be shared with the customer if possible.)

3. Check malfunction indicator lamp (EPS warning lamp)

operation referring to MALFUNCTION INDICATOR LAMP

(EPS WARNING LAMP) CHECK.

4. Check DTC referring to DTC CHECK in this Section and

record the DTC(s).

5. Clear DTC if any malfunction DTC exists referring to DTC

CLEARANCE in this section, then recheck DTC.

6. Is any malfunction DTC detected?

Go to Step 2. Go to Step 3.

2. 1. Inspect and repair referring to applicable 3.8 DTC TABLE in

this Section.

2. Clear the DTC referring to 3.6 DTC CLEARANCE in this

Section.

3. Does the trouble recur?

Go to Step 5. Go to Step 4.

3. 1. Test drive the vehicle and turn steering wheel fully to the right

and left during test driving; refer WARNING. Check if any

trouble exists.

2. Inspect and repair basic parts refer to Section 3,

1.1 GENERAL DIAGNOSIS.

3. If the trouble cannot be repaired in Step 3-2, inspect and

repair, refer to 3.23 TROUBLE DIAGNOSIS (FOR TROUBLE

NOT INDICATED BY ON-BOARD DIAGNOSTIC SYSTEM)

in this Section.

4. Does the trouble recur?

Go to Step 5. Go to Step 4.

4. 5. Confirm that the problem symptom no longer exists and the

P/S system is free from any abnormal conditions. If the

repaired item is related to the malfunction DTC, clear the

DTC once and perform a test drive as in S tep 3-1 and confirm

that no DTC is indicated.

6. Is any malfunction DTC detected?

Go to Step 5. END

5. 1. Check DTC refer to 3.5 DTC CHECK in this Section.

2. Is any malfunction DTC detected? Go to Step 2. Go to Step 3.

NOTE:

• As exec ution of the DTC CLEA RANC E will cl ear all malf unction DTCs, be sure to re cord all DTCs befor e

servicing.

• When 2 or more codes are indicated, the lowest numbered code will appear first.

• If a code not listed on the DTC TABLE is displayed, then the P/S control module is faulty.

• DTC C1122 or DTC No.22 (flashing pattern: 22) is indicated when the ignition switch is ON and the engine

is not running but if DTC No.12 (flashing pattern: 12) is indicated when the engine is started, it means

nothing abno r mal.

• Current DTC and history DTC can be identified by lighting and flashing of the EPS warning lamp.

The EPS warning lamp operates as follows depending on the fault condition.

To identify current DTC, clear history DTC, refer to 3.6 DTC CLEARANCE in this Section.

Current DTC is set.

(Abnormality exists

at present.)

History DTC is set only.

(Faulty condition

occurred once in the

past but normal condi-

tion is restored at

present.)

Current DTC and his-

tory DTC exist.

EPS warning lamp after

engine started Remains ON. Turn OFF. Remains ON.

EPS warning lamp when

shorting diagnosis switch

terminal and ground

terminal

Displays current DTC. Displays history DTC. Displays current DTC and

history DTC.

CUSTOMER QUESTIONNAIRE (EXAMPLE)

3.4 EPS WARNING LAMP CHECK

1. Tu rn ign ition s witc h to ON pos i tio n (but without runnin g

engine), check that EPS warning lamp lights up. If

lamp does not light up, refer to 3.9 TABLE A - EPS

WARNING LAMP DOES NOT ILLUMINAATE WITH

IGNITION SWITCH ON POSITION BUT WITH

ENGINE NOT RUNNING in this Section. If lamp

flashes , refer to 3.10 TABLE B - EPS WARNING LAMP

FLASHES AT IGNITION SWITCH ON in this Section.

2. Start engine and check that the malfunction indictor

lamp (EPS warning light) turns OFF.

If lamp goes OFF, P/S system is in good condition.

3.5 DTC CHECK

USING TECH 2

1. Turn ignition switch to OFF position.

2. Connect Tech 2 (A) to data link connector (DLC) (1)

located b eside the d rivers side of the ins trument panel

centre facia.

3. Turn ignition switch to ON position.

4. Read DTC according to instructions displayed on

Tech 2 and print it or write it down and refer to

Section 0C TECH 2 for further details.

NOTE: If Tech 2 cannot display DTC, refer to

3.7 SERIAL DATA LINK CIRCUIT CHECK in this Section.

5. After completing the check, turn ignit ion switch to OFF

position and disconnect Tech 2 from DLC.

NOT USING TECH 2

1. Remove the glove box.

Open the glove box (1), then while pressing the glove

box stoppe r, pull out the glove b ox from the instrume nt

panel (3) and remove the glove box clip (2) and glove

box from the instrument panel.

2. Apply chocks to wheels, set shift lever to neutral

position and fully apply parking brake.

3. Start engine.

4. Using jumper wire (4), short diagnosis switch terminal

(1) to ground term inal (2) of dia gnosis conne ctor No. 2

(3).

5. Read flashing of EPS warning lamp which represents

DTC and write it down. When more than 2 DTCs are

stored in memory, each DTC is repeated 3 times

starting with the smallest DTC number in increasing

order.

For details and example of DTC, refer to

3.8 DTC TAB LE in this Section.

NOTE: DTC No.22 is indicated when the ignition switch is

ON and the e ngine i s not runni ng, but if DT C No.12 is in di-

cated when the engine is started, it means nothing abnor-

mal.

6. After completing the check, turn the ignition switch to

OFF position and disconnect jumper wire (4) from

diagnosis connector No. 2.

3.6 DTC CLEARANCE

USING TECH 2

1. Turn ignition switch to OFF position.

2. After setting the cartridge connect Tech 2 (A) to data

link connector (DLC) (1) located beside the drivers side

of the instrument panel centre facia.

3. Turn ignition switch to ON position.

4. Erase DTC according to instructions displayed on

Tech 2 refer to Section 0C TECH 2 for further details.

5. After co mpleting the check, turn ignition switc h to OFF

position and disconnect Tech 2 from DLC.

NOT USING TECH 2

1. Remove glove box, refer to 3.5 DTC CHECK in this

Section.

2. Turn ignition switch to ON position.

3. Using jumper wire, short diagnosis switch terminal (1)

to ground terminal (2) of diagnosis connector No.2 (3).

4. Conn ect and disconne ct one end of th e jumper wi re at

least 5 times within 10 seconds.

DTC clearance procedure specifi cation

(a): about 1 second

(b): within 10 seconds

5. Perform DTC CHECK and confirm that normal DTC

(DTC No.12) is displayed and not malfunction DTC.

3.7 SERIAL DATA LINK CIRCUIT CHECK

CAUTION: Be sure to perform 3.3 SYSTEM CHECK FLOW TABLE before starting diagnosis according

to flow table.

Legend

DIAGNOSTIC FLOW TABLE

1. Main fuse box 8. EPS warning lamp 13. To immobiliser control module

2. P/S fuse (30 A) 9. To vehicle speed sensor 14. Ground on body

3. Ignition switch (VSS) 15. Ground on engine block

4. Circuit fuse box 10. To circuit fuse box 16. P/S control module

5. IG meter fuse (15 A) 11. Data link connector (DLC) 17. Connector G24

6. Combination meter 12. To ECM, SDM and ABS (viewed from harness side)

7. Speedometer hydraulic unit/control module

assembl y if (equi pped )

Step Action Yes No

1. Was “SYSTEM CHECK FLOW TABLE” per-

formed? Go to Step 2. Go to 3.3 SYSTEM

CHECK FLOW TABLE in

this Section.

2. 1. Make sure that Tech 2 is functioning

correct ly and th e corr ect cartri dge for t he

P/S system is used.

2. Turn ignition switch to OFF position.

3. Check proper connection of Tech 2 to

DLC.

4. Is connection in good condition?

Go to Step 3. Connect Tech 2 to DLC

correctly.

Figure 1 for Step 4

3.8 DTC TABLE

CAUTION: Perform 3.3 SYSTEM CHECK FLOW TABLE in this Section before starting diagnosis

according to flow table of each DTC.

3. 1. Check if communication is possible by

trying communication with other

controller (ECM, ABS hydraulic unit/

contro l module ass embly (if eq uipped) o r

SDM).

Is it possible to communicate with other con-

troller?

Go to Step 4. Repair open in common

section of serial data cir-

cuit (BLU wire circuit)

used by all controllers or

short to ground or power

circuit which has

occurred somewhere in

serial data circuit (BLU

wire circuit).

4. 1. With ignition switch in OFF position,

disconnect 8-pin (G24) connector from P/

S control module.

2. Check proper connection at G24-3 (BLU

wire) (2) terminal fo r serial data circuit.

3. If OK, then check resistance between

G24-3 (BLU wire) terminal and BLU wire

terminal for serial data circuit in DLC (1).

4. Is resistance 1 Ω or less?

Substitute a known-good

P/S control module and

recheck.

Repair high resistance or

open in BLU wire circuit

for P/S system.

Step Action Yes No

3.0 0.30.3 0.30.3 1.0 3.0 3.0

21 21

Example : When VSS circuit fail (DTC 1121, DTC No.21) is set

“EPS” light

Turn ON

Turn OFF

TIME

(sec.)

DTC (displayed

on Tech 2)

“EPS” light flashing pattern

DTC (indicated

by EPS light

flashing pattern) Model DI AGNOSTIC

ITEM DIAGNOSIS

NO DTC 12 Normal

This code appears

when none of the

other codes are

identified.

C1111 11

Torque sensor

Diagnose trouble

according to the

DIAGNOSTIC

FLOW TABLE

corresponding to

each code No.

C1113 13

C1114 14

C1115 15

C1116 16

C1121 21

VSS signa lC1123 23

C1124 24

C1122 22 Engine speed

signal

C1141 41

Motor

C1142 42

C1143 43

C1144 44

C1145 45

C1151 51 Clutch

C1152 52

P/S control moduleC1154 54

C1155 55

C1153 53 P/S control module

power supply

3.9 TABLE A - E PS WARNING LAMP DOES NOT ILLUMINATE WITH IGNITION

SWITCH ON AND WITH ENGINE NOT RUNNING

CIRCUIT

Legend

1. Main fuse box 5. Circuit Fuse box 9. Diagnosis switch terminal

2. Ignition switch 6. EPS warning lamp 10. Ground terminal

3. P/S fuse (30A) 7. Combination meter 11. P/S control module

4. IG fuse (15A) 8. Diagnosis connector No.2 12. Connector G24 (viewed from

harness side)

INSPECTION

Step Action Yes No

1. 1. S et parking brak e.

2. Note combination meter when ignition

switch is turned to ON position.

Does the BRAKE indicator (warning lamp)

come ON?

Go to Step 2. BLK/YEL, BLK/WHT wire

circuit or

IG fuse open or short to

ground.

2. 1. Ignition switch OFF.

2. Remove and inspect P/” fuse.

3. Is fuse in good condition?

Reinstall P/S fuse, and

then go to Step 3. Check BLK/RED wire cir-

cuit for short to ground.

If OK, replace P/S fuse.

3. 1. Turn ignition switch OFF.

2. Remove and inspect EPS warning lamp

bulb and combination meter referring to

Section 8, 2.10 COMBINATION METER.

Are they in good conditi on?

Reinstall EPS warning

lamp bulb and combina-

tion meter , and then go to

step 4.

Replace EPS warning

lamp bulb or combination

meter.

4. 1. With ignition switch OFF, disconnect P/S

control module con nector (G24).

2. Check proper connection to P/S control

module at G24-1 terminal.

3. If OK, check voltage between G24-1

(BLK/RED wire) terminal and body

ground with ignition switch ON.

Is it 10 – 14 V?

Go to Step 5. WHT/RED or BLK/RED

wire circuit open or short

to ground.

5. 1. Check proper connection to P/S control

module at G24-8 terminal.

2. If OK, check voltage between G24-8

(BLK/WHT wire) terminal and body

ground with ignition switch ON.

Is it 10 – 14 V?

Go to Step 6 BLK/WHT wire circuit

open or short to ground.

6. 1. Check proper connection to P/S control

module at G24-5 terminal.

2. If OK, check voltage between G24-5

(YEL wire) terminal and body ground with

ignition switch ON.

Is it 10 – 14 V?

Substitute a known -g ood

P/S control module and

re-check.

Check YEL wire circuit

open or short to ground.

3.10 TABLE B - EPS WARNING LAMP FLASHES

WITH IGNITION SWITCH ON

CIRCUIT

Refer to 3.9 TABLE-A in this Section for System Circuit Diagram.

3.11 TABLE C - EP S WARNING LAMP DOES NOT FLASH, REMAINS ON OR OFF,

EVEN WITH DIAGNOSIS SW ITC H TERMINAL GROUNDED

CIRCUIT

Refer to 3.9 TABLE-A in this Section for System Circuit Diagram.

Step Action Yes No

1. 1. Check diagnosis connector No.2

Is it connected to diagnosis switch terminal (8)

and ground terminal (9) in diagnosis connector

No.2 by jumper wire?

Disconnect jumper wire

from diagnosis connec-

tor No. 2.

Go to Step 2.

2. 1. Check voltage between diagnosis switch

terminal of diagnosis connector No.2 and

body ground with ignition switch ON.

Is it 4 – 6 V?

Substitute a known-good

P/S control module and

recheck.

PPL/WHT wire circuit

short to ground.

Step Action Yes No

1. 1. Inspect jumper wire connection between

diagnosis switch and ground terminals on

diagnosis connector No.2.

Is it securely co nnec te d.

Go to Step 2. Properly connect jumper

wire diagnosis switch and

ground terminals on diag-

nosis connector No.2.

2. 1. With ignition switch OFF, disconnect P/S

control module connector (G24).

2. Check proper connection to P/S control

module at G24-4 terminal.

3. If OK, check resistance between G24-4

(PPL/WHT wire) terminal and diagnosis

switch terminal of diagnosis connector

No.2.

Is there contin ui ty?

Go to Step 3. PPL/WHT wire circuit

open.

3. 1. Check proper connection to P/S control

module at G24-2 terminal.

2. If OK, check resistance between G24-2

(BLK wire) terminal and body ground.

Is there contin ui ty?

Go to Step 4. BLK wire circuit open.

4. 1. Check proper connection to P/S control

module at G24-5 terminal.

2. If OK, check voltage between G24-5

(YEL wire) terminal and body ground with

ignition switch ON.

Is it 10 – 14 V?

Substitute a known-good

P/S control module and

recheck.

YEL wire circuit or inside

of combination meter

short to other circuit or

ground.

3.12 DTC C1111 (DTC NO.11) TORQUE SENSOR MAIN CIRCUIT FAILURE

3.13 DTC C1113 (DTC NO.13) TORQUE SENSOR MAIN AND SUB CIRCUIT FAILURE

3.14 DTC C1115 (DTC NO.15) TORQUE SENSOR SUB CIRCUIT FAILUR E

Legend

1. Main fuse box 5. Circuit fuse box 8. Connector G24

2. Ignition switch 6. P/S control module (viewed from harness side)

3. P/S fuse (30A) 7. Torque sensor 9. Connector G24-1

4. IG fuse (15A) (viewed from harness side)

Step Action Yes No

1. 1. Was SYSTEM CHECK FLOW TABLE

performed? Go to STEP 2. Go to 3.3 SYSTEM

CHECK FLOW TABLE.

2. 1. Is DTC C1114 (DTC No.14) or C1116

(DTC No.16) indicated? Go to flow table corre-

sponding to each DTC

No.

Go to STEP 3.

3. 1. Check proper connection for connector

(G24-1) to P/S control module.

2. If OK, check t orque se ns or and its circuit.

Refer to 4.4 TORQUE SENSOR in this

Section.

3. Is torque sensor in good condition?

Substitute a known-good

P/S control module and

recheck.

Replace steering column

assembly and recheck.

3.15 DTC C1114 (DTC NO.14) TORQUE SENSOR 5V

POWER SUPPLY CIRCUIT FAILURE

Legend

Figure 1 for Step 2

1. Main fuse box 5. Circuit fuse box 8. Connector G24

2. Ignition switch 6. P/S control module (viewed from harness side)

3. P/S fuse (30A) 7. Torque sensor 9. Connector G24-1

4. IG fuse (15A) (viewed from harness side)

Step Action Yes No

1. Was SYSTEM CHECK FLOW TABLE per-

formed? Go to STEP 2. Go to 3. 3 SYSTEM

CHECK FLOW TABLE in

this Section.

2. 1. Remove steering column hole cover.

2. Check proper connection for connector

(G24-1) to P/S control module.

3. If OK, turn ignition switch ON.

4. Check voltage between G24-1-2 (BLU

wire) terminal of connector (G24-1) and

body ground with connector (G24-1)

connected to P/S control module.

Is it about 5 V?

Go to STEP 3. Repair high resistance,

open or short to power

circuit or ground in 5V

power supply (BLU wire)

circuit.

3. 1. Check torque sensor and its circuit. Refer

to 4.4 TORQUE SENSOR in this Section.

Is torque sensor in good condition?

Substitute a known-good

P/S control module and

re-check.

Replace ste ering colu mn

assembly and recheck.

3.16 DTC C1116 (DTC NO.16) TORQUE SENSOR

8V POWER SUPPLY CIRCUIT FAILURE

Legend

Figure 1 for Step 2

1. Main fuse box 5. Circuit fuse box 8. Connector G24

2. Ignition switch 6. P/S control module (viewed from harness side)

3. P/S fuse (30A) 7. Torque sensor 9. Connector G24-1

4. IG fuse (15A) (viewed from harness side)

Step Action Yes No

1. Was SYSTEM CHECK FLOW TABLE

performed?Go to STEP 2. Go to 3.3 SYSTEM

CHECK FLOW TABLE in

this Section.

2. 1. Remove steering column hole cover.

2. Check proper connection for connector

(G24-1) to P/S control module.

3. If OK, turn ignition switch ON.

4. Measur e voltage between G24-1-1 (R ED

wire) terminal of connector (G24-1) and

body ground with connector (G24-1)

connec ted to P/S co ntrol modul e.

Is it about 8 V?

Go to STEP 3. Repair high resistance,

open or short to power

circuit or ground in 8V

power supply (RED wire)

circuit.

3. 1. Check torque sensor and its circuit. Refer

to 4.4 TORQUE SENSOR in this Section.

Is torque sensor in good condition?

Substitute a known-good

P/S control module and

recheck.

Replace steering column

assembly and recheck.

3.17 DTC C1121/C1123/C1124 (DTC NO.21/23/24 ) VSS CIRCUIT FAILURE

Legend

Figure 1 for Step 2

1. Main fuse box 5. Circuit fuse box 9. To VSS

2. Ignition switch 6. EPS warning light 10. P/S control module

3. P/S fuse (30A) 7. Speedometer 11. Connector G24

(viewed from harness side)

4. IG fuse (15A) 8. Com binati on mete r

Step Action Yes No

1Was SYSTEM CHECK FLOW TABLE performed? Go to STEP 2. Go to 3.3 SYSTEM

CHECK FLOW TA BLE

in this Section.

21) Ignition switch OFF.

2) Remove s teering column lower cover.

3) Disconnect connector (G24) from P/S control

module.

4) Check prope r connec ti on to P/S co ntrol mod-

ule at G24-7 (PPL wire) terminal.

5) If OK, connect voltmeter between G24-7 (PPL

wire) terminal and body ground with connector

(G24 ) connec te d.

6) Hoist rear end of vehicle and lock rear right

tyre.

7) Turn rear left tyre quickly with ignition switch

ON.

Does voltmeter indicate deflection between 0 – 1 V

and 9 – 11 V a few times while tyre is turned one

revolution?

Check intermittent trou-

ble. Refer to Section

OA INTERMITTENT

AND POOR CONNEC-

TION.

If OK, substitute a

known-good P/S con-

trol module and

recheck.

Repair VSS or its (PPL

wire) circuit.

3.18 DTC C1122 (DTC NO.22) ENGINE SPEED SIGNAL CIRCUIT FAILURE

Legend

1. Main fuse box 4. IG fuse (15A) 7. P/S control module

2. Ignition switch 5. Circuit fuse box 8. Connector G24

3. P/S fuse (30A) 6. ECM (viewed from harness side)

Step Action Yes No

1. Was SYSTEM CHECK FLOW TABLE

performed? Go to STEP 2. Go to 3.3 SYSTEM

CHECK FLOW TABLE in

this Section.

2. 1. Recheck DTC with engine running.

Is DTC C1122 (DTC No.22) indicated? Go to STEP 3. It is nothing abnormal for

DTC C1122 (DTC

No.22). P/S system is in

normal condition.

3. 1. Check proper connection to P/S control

module and ECM at each BRN wire

terminal (P/S control module side: G24-6

terminal, ECM side: Refer to Section 6E1

ENGINE AND EMISSION CONTROL

SYSTEM), then check intermittent trouble.

Refer to Section 0A INTERMITTENT

TROUBLE.

2. If they are OK, check high resistance, open

or short to power circuit or ground in BRN

wire circuit.

Is check result in good condition?

Substitute a known-

good P/S control mod-

ule and recheck.

Repair.

3.19 DTC C1141/C1142/C1143/C1144/C1145 (DTC NO.41/42/43/44/45)

MOTOR CIRCUIT FAILURE

Legend

Figure 1 for Step 2

1. Main fuse box 5. Circuit fuse box 8. Connector G24

(viewed from harness side)

2. Ignition switch 6. P/S control module

3. P/S fuse (30A) 7. Motor and clutch 9. Connector G24-2

(viewed from harness side)

4. IG fuse (15A)

Step Action Yes No

1. Was SYSTEM CHECK FLOW TABLE

performed? Go to STEP 2. Go to 3.3 SYSTEM

CHECK FLOW TABLE in

this Section.

2. 1. Remove steering column hole cover.

2. Check proper connection for 4-terminals

connector (G24-2) to P/S control module.

3. If OK, start engine.

4. Check voltage between G24-2-2 (BLK

wire) terminal and body ground and G24-

2-1 (RED wire) terminal and body ground

with connector (G24-2) connected to P/S

control module.

Are they 5 – 7 V with the steering wheel held at

straight ahe ad pos ition?

Go to STEP 3. Repair poor connection,

high resistance, open or

short to power circuit or

ground in G24-2-2 (BLK

wire) or G24-2-1 (RED

wire) circuit.

3. 1. Check motor and its circuit. Refer to 4.5

MOTOR ASSEMBLY (WITH CLUTCH

INCORPORATED in this Section.

Is motor and clutch in good condition?

Substitute a known-

good P/S control mod-

ule and recheck.

Replace steering column

assembly and recheck.

3.20 DTC C11 51 (DTC NO.51) CLUTCH CIRCUIT FAILURE

Legend

1. Main fuse box 5. Circuit fuse box 8. Connector G24

(viewed from harness side)

2. Ignition switch 6. P/S control module

3. P/S fuse (30A) 7. Motor and clutch 9. Connector G24-2

(viewed from harness side)

4. IG fuse (15A)

Step Action Yes No

1. Was SYSTEM CHECK FLOW TABLE

performed?Go to STEP 2. Go to 3.3 SYSTEM

CHECK FLOW TABLE in

this Section.

2. 1. Remove steering column hole cover.

2. Check proper connection for connector

(G24-2) to P/S control module.

3. If OK, start engine.

4. Check voltage between G24-2-4 (BLK

wire) terminal and body ground with

connector (G24-2) connected to P/S

control module.

Is it 0 V?

Go to STEP 3. Repair poor connection,

high resistance, open or

short to power circuit or

ground in G24-2-4 (BLK

wire) ci rcuit.

3. 1. Check voltage between G24-2-3 (BLK

wire) terminal and body ground with

connector (G24-2) connected to P/S

control module.

Is it 10 – 14 V with steering wheel held at

straight ahead position?

Go to STEP 4. Repair poor connection,

high resistance, open or

short to power circuit or

ground in G24-2-3 (BLK

wire) ci rcuit.

4. 1. Check motor and its circuit. Refer to 4.5

MOTOR ASSEMBLY (WITH CLUTCH

INCORPORATED).

Is motor and clutch in good condi tio n?

Substitute a known-good

P/S control module and

recheck.

Replace steering column

assembly and recheck.

Figure 1 for Step 2

Figure 2 for Step 3

3.21 DTC C1153(DTC NO.53) P/S CONTROL MODULE

POWER SUPPLY CIRCUIT FAILURE

Legend

Figure 1 for Step 2

3.22 DTC C1152/C1154/C1155 (DTC NO.52/54/55) P/S CONTROL MODULE FAILURE

Substitute a known-good P/S control module and recheck.

1. Main fuse box 4. IG fuse (15A) 7. Connector G24

(viewed from harness side)

2. Ignition switch 5. Circuit fuse box

3. P/S fuse (30A) 6. P/S control module

Step Action Yes No

1. Was SYSTEM CHECK FLOW TABLE

performed?Go to STEP 2. Go to 3.3 SYSTEM

CHECK FLOW TABLE in

this Section.

2. 1. Remove steering column hole cover.

2. Check P/S fuse and proper connection to

P/S control module at G24-1 (BLK/WHT

wire) terminal.

3. If OK, check voltage between G24-1

termina l and body gro und with con nector

(G24) connected to P/S control module.

Is it 10 – 14 V?

Check intermittent trou-

ble. Refer to Section 0A

INTERMITTENT AND

POOR CONNECTION.

If OK, substitute a known-

good P/S control module

and rechec k.

Repair poor connection

or high resistance in G24-

1 (BLK/RED wire) circuit.

3.23 TROUBLE DIAGNOSIS

(FOR TROUBLE NOT INDICATED BY ON-BOARD DIAGNOSTIC SYSTEM)

This section describes trouble diagnosis of the P/S system parts when the fault is not indicated by the on-

board dia gno sti c system (sel f- di agno st ic function ).

When there is no malfunction indicated by the on-board diagnostic system (self-diagnosis function) and the

basic steering parts described in the diagnostic table, refer to Section 3, 1.1 GENERAL DIAGNOSIS, are all in

good condition, check the following power steering system parts which may be a possible cause for faulty

steering.

Condition Possible Cause Correction

Steering wheel feels

heavy (Perform

STEERING FORCE

INSPECTION before

diagnosis.)

Steering wheel installed improperly (twisted) Install steering wheel correctly.

Poor performance of torque sensor Check torque sensor. Refer to

4.4 TORQUE SENSOR in this

Section.

Poor performance of motor and clutch Check motor and clutch. Refer to

4.5 MOTOR ASSEMBLY (WITH

CLUTCH INCORPORATED.

Faulty steering column Replace.

Poor performance of VSS Check VSS. Refer to Section 6E1

ENGINE AND EMISSION

CONTROL SYSTEM.

Vehicle pulls to one

side during straight

driving

Poor performance of torque sensor Check torque sensor. Refer to

4.4 TORQUE SENSOR in this

Section.

Poor recovery from

turns Poor performance of torque sensor Check torque sensor. Refer to

4.4 TORQUE SENSOR in this

Section.

Faulty steering column Replace.

3.24 INSPECTION OF THE P/S CONTROL MODULE AND ITS CIRCUITS

The P/S co ntrol modul e (1) and its circuits can be c hecked

at the P/S control module wiring connectors (2) by measur-

ing voltage and resistance.

CAUTION: P/S control module cannot be checked by

itself. It is strictly prohibited to connect a voltmeter or

ohmmeter to the P/S control module with the connec-

tor disconnected from it.

VO LTAGE CHECK

1. Remove steering column hole cover with ignition

switch in OFF position.

2. Chec k voltage at eac h te rm in al w ith co nnec to rs ( 2) st il l

connected to the P/S control module.

NOTE: As each terminal voltage is affected by the battery

voltage, confirm that it is 11V or more when the ignition

switch is ON.

NOTE: ✱: The voltage of this circuit may fail to check by voltmeter. If so, use an oscilloscope.

TERMINAL

NO. CIRCUIT NORMAL VOLTAGE CONDITION

G24-2 Ground – –

G24-1 P/S control module

power supply from battery 10 – 14V –

G24-8 P/S control module

power supp ly from igni-

tion switch

10 – 14V Ignition switch ON

G24-7 VSS ✱ Indicator

deflection repeated

0 – 1V and 9 – 11V

Ignition switch ON

Front left tyre turned quickly with

right tyre locked

G24-6 Engine speed signal ✱ Indicator

deflection repeated

0 – 1V and 10 – 14V

Engine idling

G24-5 EPS light 0V EPS warning lamp ON

G24-4 Diagnosis switch terminal 4.6V Ignition switch ON

G24-3 Data link connector – –

G24-2-2 Motor output 2 5 – 7V Engine idling and steering wheel

held at straight ahead position

G24-2-1 Motor output 1 5 – 7V Engine idling and steering wheel

held at straight ahead position

G24-2-4 Clutch output 2 0V –

G24-2-3 Clutch output 1 10 – 14V Engine idling

G24-1-5 Torque sensor (Main) About 2.5V Ignition switch ON and steering

wheel held at straight ahead posi-

tion

Check voltage between G24-1-5

and G24-1- 3 terminals

G24-1-4 Torque sensor (Sub) About 2.5V Ignition switch ON and steering

wheel held at straight ahead posi-

tion

Check voltage between G24-1-4

and G24-1- 3 terminals

G24-1-3 Torque sensor (GND) 0V –

G24-1-2 5V power supply

for torque sensor About 5V Ignition switch ON

Check voltage between G24-1-2

and G24-1- 3 terminals

G24-1-1 8V power supply

for torque sensor About 8V Ignition switch ON

Check voltage between G24-1-1

and G24-1- 3 terminals

3.25 STEERING WHEEL PLAY INSPECTION

Check the steering wheel for looseness or rattle by trying to

move it in its shaft direction and lateral direction.

If found defective, repair or replace.

Check steering wheel play, holding the vehicle in a straight

forward position on the ground and with the engine not run-

ning.

If steering wheel play is not within specification, inspect as

follows and replace if found defective.

• Tie rod end ball stud for wear

• Lower ball joint for wear

• Steering shaft joint for wear

• Steering pinion or rack gear for wear or breakage

• Each part for looseness

3.26 STEERING FORCE INSPECTION

1. Place vehicle on level road and set steering wheel in

straight-ahead position.

2. Check that tyre inflation pressure is as specified.

(Refer to the TYRE PLACARD on the vehicle.)

3. Remove drivers airbag (inflator) module, refer to

Section 3C, 3.2 DRIVER AIRBAG (INFLATOR)

MODULE REMOVAL.

4. Start engine.

5. With the engine idling, measure the steering force by

placing torque wrench on steering wheel nut and

turning torque wrench.

6. Install driver airbag (inflator) module, refer to

Section 3C, 3.2 DRIVER AIRBAG (INFLATOR)

MODULE INSTALLATION.

STEERING WHEEL PLAY (a) 0 - 30 mm

STEERING FORCE LESS THAN 6.4 Nm

4. ON-VEHICLE SERVICE

4.1 STEERING COLUMN ASSEMBLY

REMOVAL

Refer to Section 3C STEERING WHEEL AND COLUMN for removal and installation of steering column

assembly but perform the following steps first.

• Remove steering hole cover.

• Disconnect all couplers from the P/S control module.

CAUTION: Never disassemble the steering column assembly, remove the torque sensor or motor

assembly (with clutch incorporated). Performing any of these prohibited services will affect original

performance of the EPS system.

4.2 CHECKING STEERING COLUMN ASSE MBLY AND LOWER SHAFT FOR

ACCIDENT DA MAGE

NOTE: Vehicles involved in accidents resultin g in body damage , where steering column has been impacted

(or airbag deployed) may have a damaged or misaligned steering column.

CHECKING PROCEDURE

Refer to Section 3C, 3.9 CHECKING STEERING COLUMN ASSEMBLY AND LOWER SHAFT FOR

ACCIDENT DAMAGE.

4.3 P/S CONTROL MODULE

REMOVAL

1. Disconnect negative cable at battery.

2. Remove steering column hole cover.

3. Disconnect connectors (1) from the P/S control

module.

4. Remove the P/S control module (2) from the steering

column assembly.

INSTALLATION

Reverse removal procedure for installation, noting the fol-

lowing.

• Tighten P/S control module screw (a) to specified

torque

P/S CONTROL MODULE SCREW

TORQUE SPECIFICATION (a) 3 Nm

4.4 TORQUE SENSOR

ON-VEHICLE INSPECTION

1. Remove steering column hole cover.

2. Turn ignition switch to ON position

3. With the engine not running, check the voltage

between terminals of the torque sensor connector

while still connected to the P/S control module.

If check result is not satisfactory, replace steering

column assembly.

Torque sensor specification

4.5 MOTOR ASSEMBLY (WITH CLUTCH INCORPORATED)

ON-VEHICLE INSPECTION

1. Remove steering column hole cover.

2. With the ignition switch in OFF position, disconnect

motor and clutch connector (1) from the P/S control

module.

3. Check the resistance between terminals of motor and

clutch connector (1).

If check result is not as specified below, replace

steering column assembly.

Motor and clutch circuit resist ance

4. Chec k continui ty between te rminal o f motor and clutch

connector (1) and body ground.

If check result is not as specified below, replace

steering column assembly.

Motor and clutch circuit resistance (to bo dy gr ound)

Steering

wheel

turned

fully left

Steering wheel

held at straight

ahead position

Steering

wheel

turned fully

right

Main sensor

(G24-1-4 –

G24-1-3) 1.5 V below About 2.5 V Above 3.5 V

Sub sensor

(G24-1-5 –

G24-1-3) 1.5 V below About 2.5 V Above 3.5 V

G24-2-2 and G24-2 -1

(For motor) About 1 Ω

G24-2-4 and G24-2 -3

(For clutch) About 12 Ω

(at 20°C (68°F))

G24-2-4 and body ground No continuity

G24-2-2 and body ground No continuity

5. Connect battery (1) between G24-2-2 and G24-2-1.

Check that motor rotates smoothly, then measure

current bet ween G24-2-1 and G24-2-2 using amm eter

(2) as shown in figure .

If check result is not satisfactory, replace steering

column assembly.

6. Connect battery (1) between G24-2-4 and G24-2-3,

then check that clutch operation sound is heard.

If check result is not satisfactory, replace steering

column assembly.

STANDARD MOTOR AND CLUTCH

CIRCUIT CURRENT (REFERENCE

VALUE) 0.65 A

5. SPECIAL TO OLS

NOTE: Refer to Section 0A GENERAL INFORMATION – 7. CONSOLIDATED TOOLS for a detailed list of

special tools and the local equivalent if one is available

NOTE:

(A): This kit includes the following items

Tech 2 kit

See NOTE (A)

1. Tech 2 5. Cigar ett e cable 9. RS232 ada ptor

2. PCMCIA card 6. DLC loopback adaptor 10. RS232 loopback connector

3. DLC cable 7. Battery power cable 11. Storage case

4. SAE 16/19 adaptor 8. RS232 cable 12. Power supply