V.TCC Diagnosis

The following procedure was developed to systematically test and diagnose TCC operation and should be followed in the listed sequence to accurately diagnose this system.

FIGURE 4 - TCC ELECTRICAL TEST:

FIGURE 5 - TCC HYDRAULIC DIAGNOSIS:

For [1][2]Torque Converter Clutch diagnosis, proceed to Figure 4, TCC Electrical Test. TCC problem remains after completing electrical test, perform Hydraulic Diagnosis, Figure 5.

FIGURE 6 - DFI TRANSMISSION CIRCUIT:

On Figure 6, DFI Transmission Circuit, the center bulkhead connector shown is for 1984 vehicles only. For location of terminals and connector illustration on 1982 or 1983 vehicles, refer to the appropriate model year Service Information Manual.

FIGURE 7 - TEE FITTING INSTALLATION:

Refer to Figure 7 for illustration of Tee Fitting for hydraulic diagnosis.

NOTE ON INTERMITTENTS: If the electrical and hydraulic test procedures did not define the cause of the code 39, an intermittent electrical or hydraulic condition could exist.

ELECTRICAL INTERMITTENTS: Could be due to the adjustment of the brake switches. The ECM does not test for the TCC code if it sees the brake applied through the Cruise Control brake signal on circuit #86. This is because the TCC brake switch is also open under this condition. If the TCC brake switch is adjusted such that it opens before the Cruise Control brake release switch, a code 39 could be set if the operator were to keep the brake pedal applied just enough to open the TCC switch but not the Cruise Control switch. To check the adjustment of both switches, attach a test light from the purple wire of the TCC brake switch to ground and another test fight from the dark green wire of the Cruise Control brake switch to ground. With the ignition on, both test lights should be lit. When the brake pedal is depressed 1/8" to 1/2", the test light on the Cruise Control brake release switch should turn off first followed by the light at the TCC brake switch. Intermittent electrical conditions could also be a result of poor connections or wiring intermittently shorted or open.

HYDRAULIC INTERMITTENTS: Could be due to a malfunction of one or more of the following: converter clutch apply valve, TCC solenoid, or poppet valves on converter clutch plate inside the torque converter.