
Automatic Transmission – 5L40-E – Hydraulic and Mechanical Diagnosis Page 7E3–2
7E3 – 2
2.10 Engine Coolant in Transmission........................................................................................................................ 26
2.11 Fluid Leak Diagnosis and Repair........................................................................................................................ 27
Methods for Locating Leaks ............................................................................................................................... 27
General Method................................................................................................................................................ 27
Powder Method................................................................................................................................................ 27
Dye and Black Light Method ............................................................................................................................ 27
Find the Cause of the Leak ................................................................................................................................. 28
Gaskets............................................................................................................................................................ 28
Seals ................................................................................................................................................................ 28
Possible Points of Fluid Leaks........................................................................................................................... 29
Transmission Fluid Pan.................................................................................................................................... 29
Case Leak........................................................................................................................................................ 29
Leak at the Torque Converter End................................................................................................................... 29
Leak at the Vent............................................................................................................................................... 29
Case Porosity Repair........................................................................................................................................... 31
2.12 Shift Solenoid Leak Test ..................................................................................................................................... 32
2.13 Range Reference Chart ....................................................................................................................................... 33
3 Symptoms Diagnosis...........................................................................................................................34
3.1 Symptoms Diagnosis Table................................................................................................................................ 34
3.2 Diagnostic Tables................................................................................................................................................ 36
Automatic Transmission Overheating ............................................................................................................... 36
Buzz Noise or High Frequency Rattle Sound.................................................................................................... 36
Degraded 1–2 and 2–1 Shifts.............................................................................................................................. 36
Degraded 2–3 and 3–2 Shifts.............................................................................................................................. 37
Degraded 4–5 Shift .............................................................................................................................................. 37
Drives with Selector Lever in Position N........................................................................................................... 37
Fifth Gear Only..................................................................................................................................................... 37
First and Second Gears Only.............................................................................................................................. 38
First Gear Only..................................................................................................................................................... 38
First, Fourth and Fifth Gears Only...................................................................................................................... 38
Fluid Pressure High or Low ................................................................................................................................ 39
Harsh Shift 4–5, or 5–4 ........................................................................................................................................ 40
Harsh Shift D–R.................................................................................................................................................... 40
Harsh Shifts.......................................................................................................................................................... 41
Harsh Torque Converter Clutch (TCC) Apply.................................................................................................... 41
Inaccurate Shift Points........................................................................................................................................ 42
No Drive in All Ranges ........................................................................................................................................ 42
No Engagement of Torque Converter Clutch (TCC) ......................................................................................... 43
No Engine Braking............................................................................................................................................... 43
No Engine Braking in First Gear......................................................................................................................... 44
No Engine Braking in First, Second and Third Gear......................................................................................... 44
No Engine Braking in Second Gear.................................................................................................................... 44
No Engine Braking in Third Gear........................................................................................................................ 45
No Fifth Gear........................................................................................................................................................ 45
No First Gear........................................................................................................................................................ 45
No Fourth Gear or Slips in Fourth Gear............................................................................................................. 46
No Reverse or Slips in Reverse.......................................................................................................................... 46
No Second Gear................................................................................................................................................... 46
No Third Gear....................................................................................................................................................... 47
Noise in Random Ranges.................................................................................................................................... 47
Popping Noise...................................................................................................................................................... 47
Power Mode Switch / Indicator Always On or Inoperative ............................................................................... 47
Second and Third Gears Only............................................................................................................................. 47
Slips or Shudders in First Gear.......................................................................................................................... 48
Slips While Shifting ............................................................................................................................................. 48
Whine Noise Varying with RPM or Fluid Pressure............................................................................................ 48