W T E C I I I E L E C T R O N I C C O N T R O L S T R O U B L E S H O O T I N G M A N U A L
Main code 55 indicates the C3 clutch is the oncoming clutch in a shift and the C3 pressure switch did not close at
the end of the shift. When this code is set, the DO NOT SHIFT response and Neutral with No Clutches is
commanded. On the N1 to R shift the transmission is commanded to the previous range. Additional codes could be
logged for other shifts where X indicates the range from and Y indicates the range to.
When an ECU with a version 8 or 8A calibration is used with a pre-TransID transmission, 55 XX codes
are set because the ECU sees wire 195 is open. To correct this condition, convert to a TID 1 internal
harness or install Adapter P/N 200100 available from St. Clair Technologies.
When sump temperature is below 10°C (50°F), and transmission fluid is C4 (not DEXRON®), follow
this procedure when making directional change shifts:
To shift from forward to reverse; select N (Neutral) and then R (Reverse).
Failure to follow this procedure may cause illumination of the CHECK TRANS light and then
transmission operation will be restricted to N (Neutral).
Active Indicator Clearing Procedure:
Manual subcode 87 only
Intermittent connections or lack of battery-direct power and ground connections may cause this and
Check battery and ECU input voltages before troubleshooting.
Do not bring the transmission to operating temperature if the problem occurs at sump temperatures
below that level. Do troubleshooting at the temperature level where the problem occurs.
1. After the transmission is at operating temperature, allow vehicle engine to idle on level ground for
34 minutes. Check transmission fluid level. If improper fluid level is found, correct as necessary.
Improper fluid level could be the cause of the code (not enough or too much fluid may produce
inadequate clutch pressure).
2. Connect a pressure gauge and check main pressure. If pressure is not adequate, the pump is
possibly worn. See Appendix B for main pressure specifications.
Oncoming C3PS (after shift), LR shift
Oncoming C3PS (after shift), 1R shift
Oncoming C3PS (after shift), 2R shift
Oncoming C3PS (after shift), N1R shift
Oncoming C3PS (after shift), N1L to R shift
Oncoming C3PS (after shift), X to Y shift
CODE 55 XX ONCOMING C3 PRESSURE SWITCH (AFTER SHIFT)