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 52 indicates a failed C3 pressure switch test. When a shift is commanded and C3 is the offgoing clutch,
the ECU expects the C3 pressure switch to open within a period of time after the shift is commanded. If the ECU
does not see the switch open, it assumes C3 has not released. If conditions for a shift exist, the shift is retried. If the
C3 pressure switch still remains closed, the code is logged and the DO NOT SHIFT response is commanded. If the
code is set during a direction change, neutral with no clutches is commanded, otherwise 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.
C3 tests are turned off below a calibrated temperature of 32ºC (25°F).
Active Indicator Clearing Procedure:
Before troubleshooting, read Paragraph 56. Also, check battery and ECU input voltages.
Intermittent connections or lack of battery-direct power and ground connections may cause this and
1. Use the Pro-Link® diagnostic tool to check the state of the C3 pressure switch.
2. Check the C3 pressure switch wiring for a short-to-ground or a switch stuck closed (refer to code
32XX). If a short is found, isolate and repair; or replace the switch if it is stuck closed.
3. If a fault is not found with the C3 pressure switch or circuitry, connect a pressure gauge to the C3
4. Drive the vehicle to make the shift indicated by the subcode or use the DDR clutch test mode.
Compare actual C3 pressure value with the table of specifications in Appendix B.
R2 shift (R to NNC to 2)
CODE 52 XX OFFGOING C3 PRESSURE SWITCH TEST DURING SHIFT