Copyright © 1998 General Motors Corp.
6–51
W T E C I I E L E C T RO N I C C O N T RO L S T RO U B L E S H O OT I N G M A N UA L
Main code 32 indicates the transmission gear ratio is correct, but the C3 pressure switch is open when it should
be closed.
Active Indicator Clearing Procedure:
•
Power down
•
Manual
•
Self-clearing
NOTE:
Before troubleshooting, read Pages 6–17 and 6–18 of Section 6–5. Also, check battery and ECU input
voltages.
1. Disconnect the connectors at the ECU and the transmission. Check the C3 switch circuit for opens,
shorts to other wires, shorts-to-ground, or shorts-to-battery. If wiring problems are found, isolate
and repair. The C3 pressure switch closes at 206.8 ± 48 kPa (30 ± 7 psi). Resistance should be
2 Ohms maximum when the switch is closed and 20,000 – infinity (overlimit) Ohms when the
switch is open.
2. If problems are not found in the external harness, drain the fluid, remove the control module, and
check the internal harness for opens, shorts between wires, or shorts-to-ground (refer to the proper
transmission Service Manual). If wiring problems are found, isolate and repair (see Appendix E,
Paragraph 1–9).
3. If no wiring problems are found, replace the C3 pressure switch (refer to transmission Service
Manual).
4. If the problem recurs, use spare wires for the C3 pressure switch circuit.
5. If the problem recurs again, replace the internal harness.
6. If the condition persists, replace the ECU. If replacing the ECU corrects the problem, reinstall the
original (bad) ECU to confirm that the problem is in the ECU. If the original ECU now works,
inspect the ECU connectors for any corrosion or damage which may cause an intermittent
condition. If the original problem recurs, reinstall the replacement ECU.
Main
Code
Subcode
Meaning
32
00
C3 switch open in low range
32
33
C3 switch open in third range
32
55
C3 switch open in fifth range
32
77
C3 switch open in reverse range
CAUTION:
It is very important to correct any short-to-battery condition found. A short-to-battery can
damage a circuit in the ECU, requiring the ECU to be replaced. Replacing a failed ECU
without correcting the short-to-battery could damage the new ECU.
CODE 32 XX — C3 PRESSURE SWITCH
(Figures 6–15, 6–16)
