Cutlass Ciera V6-3300 3.3L MFI VIN N (1993)
TCC Circuit
CIRCUIT DESCRIPTION:
The purpose of the Torque Converter Clutch (TCC) feature is to eliminate the power loss of the transmission converter stage when the vehicle is in
a cruise condition. This allows the convenience of the automatic transmission and the fuel economy of a manual transaxle.
Fused battery ignition is supplied to the TCC solenoid through the brake switch, and transmission third gear apply switch. The ECM will engage
TCC by grounding CKT 422 to energize the solenoid.
The TCC will engage when:
^
Engine warmed up.
^
Vehicle speed above a calibrated value (about 33 mph, 51 km/h).
^
Transmission 3rd gear switch open.
^
Throttle position sensor output not changing, indicating a steady road speed.
^
Transmission TCC in-line switch closed.
^
Brake switch closed.
TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.
1.
Checks gauges fuse and brake switch.
2.
Checks ECM for proper operation.
3.
Checks the internal switches in the transaxle.
DIAGNOSTIC AIDS:
The scan tool only indicates when the ECM has turned "ON" the TCC driver and this does not confirm that the TCC has engaged. To determine if
TCC is functioning properly, engine rpm should decrease when the scanner indicates the TCC driver has turned "ON."
If the ECM, TCC solenoid, and control circuitry are functioning correctly and the TCC still does not apply properly, the problem may be hydraulic
or mechanical.
