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AXOD Transaxle Electrical System Diagnosis: Notes

This test should be performed ONLY if a problem has been detected in transaxle. If any of these service codes appeared during SELF-TESTS, the TEST RR - AXOD TRANSAXLE  should be performed. The following AXOD transaxle related items have malfunctioned or failed as indicated:

The following service codes are not AXOD transaxle related, but can affect converter clutch by-pass operation. Service these components before servicing AXOD transaxle codes:

The following service code indicates that a transaxle component may have caused faulty engine idle speed control:

NOTE: Ensure that all components are connected before performing test. Perform TEST RR - AXOD TRANSAXLE  on a slight upgrade or flat terrain. If any other non-AXOD related codes appear, service those codes first as they could affect electrical operation of transaxle.

AXOD Drive Cycle Test. Record and zero service codes. Warm engine to normal operating temperature. With transaxle in "D" range, lightly accelerate from a stop to 40 MPH to allow transaxle to shift into 3rd gear. Hold speed and throttle opening steady for a minimum of 15 seconds (30 seconds above 4000 feet altitude).

Shift transaxle into overdrive and accelerate lightly from 40 to 50 MPH to allow transaxle to shift into 4th gear. Hold speed and throttle opening for a minimum of 15 seconds.

With transaxle in 4th gear, throttle open and a steady speed, lightly apply and release brakes (enough to light brake lamps). Hold speed and throttle opening steady for a minimum of 15 seconds.

Brake to a stop and remain stopped for a minimum of 20 seconds with transaxle in overdrive. Perform QUICK TEST  and record service codes.

  1. Code 39 Displayed. Check that vehicle harness connector is fully attached to transaxle bulkhead connector and that vehicle harness connector terminals are fully seated in connector. If connector or terminals are not okay, repair as required and repeat QUICK TEST  . If connector and terminals are okay, go to next step.
  2. Install service jumper harness to transaxle bulkhead connector. Connect VOM positive test lead to Red wire and negative test lead to Black wire. Check resistance. If reading is between 20 and 40 ohms, go to QUICK TEST  and service codes as required. If reading is not between 20 and 40 ohms, go to next step.
  3. Connect service jumper harness Red wire to battery positive post. With engine running and transaxle in 3rd gear, connect service jumper harness Black wire to ground (to energize by-pass clutch solenoid). DO NOT connect with polarity reversed, otherwise solenoid diode will be damaged.
  4. If by-pass clutch is applied (engine RPM drops), there is no electrical component failure. By-pass clutch is operating properly. Error code may be indicating a slipping by-pass clutch. Service transaxle for a no converter clutch apply condition and repeat QUICK TEST  .
  5. If by-pass clutch is not applied (engine RPM does not drop), check main control by-pass clutch control valve (in valve body) for sticking. If valve is sticking, service valve as required. If valve is okay, go to next step.
  6. Remove by-pass solenoid. Check condition of "O" ring. Also check for contamination in/on solenoid or small hole in valve. Shake solenoid vigorously to check for free armature. If solenoid is not okay, replace by-pass clutch solenoid and repeat QUICK TEST  . If solenoid is okay, service transaxle for a no converter clutch apply condition and repeat QUICK TEST  .
    NOTE: The THS 4/3 and 3/2 pressure switches are normally open and close with hydraulic pressure. Failure of transaxle to engage in "D" will cause code 59 to be displayed. Failure of transaxle to shift into 3rd gear will cause code 69 to be displayed. Check for proper hydraulic operation before testing electrical components.
  7. Code 59 Displayed. Check that vehicle harness connector is fully attached to transaxle bulkhead connector and that vehicle harness connector terminals are fully seated in connector. If connector or terminals are not okay, repair as required and repeat QUICK TEST  . If connector and terminals are okay, go to next step.
  8. Install service jumper harness to transaxle bulkhead connector. Using VOM, check for continuity between engine ground and Blue wire. With engine running and transaxle in Neutral, VOM should indicate no continuity (infinite resistance).
  9. Shift transaxle into "D". Switch should close and resistance should be less than 10 ohms. Switch should stay closed in 1st, 2nd and 3rd gears, and then open in 4th gear. If circuit is okay, go to QUICK TEST  and service codes as required. If circuit is not okay, go to next step.
  10. Remove transaxle side oil pan. Check that internal connector with Blue wire is firmly attached to THS 4/3 pressure switch. Connector should not pull off easily or fit loosely. If connector is not okay, replace bulkhead connector and wiring assembly. Repeat QUICK TEST  . If connector is okay, go to next step.
  11. Remove connector from pressure switch by pushing on end of connector, and while pulling on connector wire. Check for continuity in bulkhead connector by measuring resistance between Blue wire and terminal inside connector just removed. If reading is more than 2 ohms, replace bulkhead connector and wiring assembly. Repeat QUICK TEST  . If reading is less than 2 ohms, go to next step.
  12. Remove THS 4/3 pressure switch. Install a 1/8-27 pipe fitting that can be connected to LOW pressure air supply in order to pressure leak and test switch closure. With 50 psi (3.5 kg/cm2 ) applied, check for ruptured diaphragm by submerging switch in clean transmission fluid. Check for bubbles coming out of small vent hole near switch terminal. If bubbles show, diaphragm has failed. Replace THS 4/3 pressure switch and repeat QUICK TEST  . If no bubbles show, go to next step.
  13. With 50 psi (3.5 kg/cm2 ) applied to switch, check resistance between switch terminal and switch case. If reading is less than 8 ohms, hydraulic pressure circuit to switch may have excessive leaks. Service transaxle as required. If reading is more than 8 ohms, replace switch. Repeat step 8), and then QUICK TEST  . Codes 39, 59, 62, 69 and 89 should no longer be displayed.
    14. NOTE: If code 62 appears in KEY ON/ENGINE OFF SELF-TEST, THS 3/2 circuit has failed. If code 62 appears in KEY ON/ENGINE RUNNING (KOER) SELF-TEST, THS 4/3 circuit has failed. If code 62 appears in both SELF-TESTS, follow entire test procedure to determine which circuit has failed.
  14. Code 62 Displayed. Remove vehicle harness connector from transaxle bulkhead connector and install service jumper harness. Using VOM, measure continuity between engine ground and White wire (THS 3/2 circuit). With engine off, VOM should indicate no continuity (infinite resistance).
  15. Measure continuity between engine ground and Blue wire (THS 4/3 circuit). With engine running and transaxle in Neutral, VOM should indicate no continuity (infinite resistance). If all readings show no continuity, go to QUICK TEST  and service codes as required. If any reading indicates continuity, go to next step.
  16. Remove transaxle side oil pan. Check for pinched, cut, or otherwise grounded wiring. If wiring is damaged, replace bulkhead connector and wiring assembly. After repairs, repeat QUICK TEST  . If THS 4/3 pressure switch wiring is okay, go to step 18). If THS 3/2 pressure switch wiring is okay, go to next step.
  17. Remove wiring from THS 3/2 pressure switch. Using VOM, check pressure switch for continuity to engine ground by connecting one lead to switch terminal and other lead to valve body. If there is no continuity (infinite resistance), go to step 19). If there is continuity to ground, replace THS 3/2 pressure switch and repeat QUICK TEST  .
  18. Remove wiring from THS 4/3 pressure switch. Using VOM, check pressure switch for continuity to engine ground by connecting one lead to switch terminal and other lead to valve body. If there is continuity to ground, replace 4/3 pressure switch and repeat QUICK TEST  . If there is no continuity (infinite resistance), go to next step.
  19. Using VOM and with wiring removed from both pressure switches, check for continuity to ground. Connect one test lead to White wire and other test lead to ground. Then connect one test lead to Blue wire and other test lead to ground. Make sure that internal terminals are not touching any metallic parts. If there is continuity to ground, replace bulkhead connector and wiring assembly. Repeat QUICK TEST  . If there is no continuity (infinite resistance), go to QUICK TEST  and service codes as required.
    NOTE: The THS 4/3 and 3/2 pressure switches are normally open and close with hydraulic pressure. Failure of transaxle to engage in "D" will cause service code 59 to be displayed. Failure of transaxle to shift into 3rd gear will cause code 69 to be displayed. Check for proper hydraulic operation before testing electrical components.
  20. Code 69 Displayed. Check that vehicle harness connector is fully attached to transaxle bulkhead connector and that terminals are fully seated in connector. If connector or terminals are not okay, repair as required and repeat QUICK TEST  . If connector and terminals are okay, go to next step.
  21. Install service jumper harness to transaxle bulkhead connector. Using VOM, check for continuity between engine ground and White wire. With engine running and transaxle in Drive, 1st, or 2nd gear, VOM should indicate no continuity (infinite resistance).
  22. When transaxle shifts into 3rd or 4th gear, the switch should close. Resistance should be less than 10 ohms between White wire and engine ground. If circuit is okay, go to QUICK TEST  and service codes as required. If circuit is not okay, go to next step.
  23. Remove transaxle side oil pan. Check that internal connector with White wire is firmly attached to THS 3/2 pressure switch. Connector should not pull off easily or fit loosely. If connector is not okay, replace bulkhead connector and wiring assembly. Repeat QUICK TEST  . If connector is okay, go to next step.
  24. Check for continuity in bulkhead connector by measuring resistance between White wire and terminal inside connector just removed. If reading is more than 2 ohms, replace bulkhead connector and wiring assembly. Repeat QUICK TEST  . If reading is less than 2 ohms, go to next step.
  25. Remove THS 3/2 pressure switch. Install a 1/8-27 pipe fitting that can be connected to LOW pressure air supply in order to pressure leak and test switch closure. With 50 psi (3.5 kg/cm2 ) applied, check for ruptured diaphragm by submerging switch in clean transmission fluid. Check for bubbles coming out of small vent hole near switch terminal. If bubbles show, diaphragm has failed. Replace THS 3/2 pressure switch and repeat QUICK TEST  . If no bubbles show, go to next step.
  26. With 50 psi (3.5 kg/cm2 ) applied to switch, check resistance between switch terminal and switch case. If reading is less than 8 ohms, hydraulic pressure circuit to switch may have excessive leaks. Service transaxle as required. If reading is more than 8 ohms, replace switch. Repeat steps 21) and 22), and then repeat QUICK TEST  . Codes 39, 59, 62, 69 and 89 should no longer be displayed.
  27. Code 89 Displayed. If code 39 is also displayed, go to step 1). Check that vehicle harness connector is fully attached to transaxle bulkhead connector and that vehicle harness terminals are fully seated in connector. If connector or terminals are not okay, repair as required and repeat QUICK TEST  . If connector and terminals are okay, go to next step.
  28. Install service jumper harness to transaxle bulkhead connector. Connect VOM positive test lead to Red wire and negative test lead to Black wire. Check resistance. If reading is between 20 and 40 ohms, go to QUICK TEST  and service codes as required. If reading is not between 20 and 40 ohms, go to next step.
  29. Remove transaxle side oil pan. Check that internal connector is fully attached to solenoid. If connector is okay, go to next step. If connector is not okay, fully engage connector and check continuity once more. If resistance is still not between 20 and 40 ohms, go to next step. If resistance is now okay, repeat QUICK TEST  .
  30. Remove connector from solenoid by pulling on wires at 2-way connector. Check solenoid continuity by connecting VOM positive test lead to solenoid positive terminal and negative test lead to solenoid negative terminal (polarity symbols are stamped on solenoid frame).
  31. If circuit is open (infinite resistance), replace solenoid and then repeat QUICK TEST  . If solenoid is okay (20 to 40 ohms resistance), replace bulkhead connector and wiring assembly. Connect all internal connectors and repeat step 28). If circuit tests okay, install oil pan. Repeat KEY ON/ENGINE OFF SELF-TEST. Code 89 should no longer be displayed.
    NOTE: The NPS is normally open and closes with hydraulic pressure. Failure of transaxle to engage in "D" or "R" will cause service code 57 to be displayed. Check for proper hydraulic pressure before testing electrical components.
  32. Code 57 Displayed. Check that vehicle harness connector is fully attached to transaxle connector and that vehicle harness terminals are fully seated in connector. If connector or terminals are not okay, repair as required and repeat QUICK TEST  . If connector and terminals are okay, go to next step.
  33. Install service jumper harness to transaxle bulkhead connector. Using VOM, check continuity between Green wire and engine ground. With engine running and transaxle in "P" or "N", VOM should indicate no continuity (infinite resistance). Shift transaxle into "R" and "D" ranges, switch should close. Resistance should be less than 10 ohms in both ranges. If circuit is okay, go to QUICK TEST  and service codes as required. If circuit is not okay, go to next step.
  34. Remove transaxle side oil pan. Check that terminal connector with Green wire is firmly attached to NPS. Connector should not pull off easily or fit loosely. If connector is not okay, replace bulkhead connector and wiring assembly. Repeat QUICK TEST  . If connector is okay, go to next step.
  35. Remove connector from NPS by pushing on end of connector while pulling on connector wire. Check for continuity in bulkhead connector by measuring resistance between Green wire and terminal inside connector just removed. If reading is more than 2 ohms, replace bulkhead connector and wiring assembly. Repeat QUICK TEST  . If reading is less than 2 ohms, go to next step.
  36. Remove NPS. Install a 1/8-27 pipe fitting that can be connected to LOW pressure air supply in order to pressure leak and test switch closure. With 50 psi (3.5 kg/cm2 ) applied, check for ruptured diaphragm by submerging switch in clean transmission fluid. Check for bubbles coming out of small vent hole near switch terminal. If bubbles show, diaphragm has failed. Replace NPS and repeat QUICK TEST  . If no bubbles show, go to next step.
  37. With 50 psi (3.5 kg/cm2 ) applied to switch, check resistance between switch terminal and switch case. If reading is 8 ohms or less, hydraulic pressure circuit to switch may have excessive leaks. Service transaxle as required. If reading is more than 8 ohms, replace switch. Repeat step 33), and then repeat QUICK TEST  . Codes 39, 59, 62, 69 and 89 should no longer be displayed.
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