DTC 80

DTC 80 Chart:

TCC Control Circuit (Component Slipping):

Circuit Description:
The PCM energizes the Torque Converter Clutch (TCC) solenoid by grounding CKT 422. The TCC solenoid allows converter release fluid to exhaust past the #9 check ball, applying the TCC. The TCC solenoid will de-energize when the PCM no longer provides a ground. When the TCC solenoid is de-energized, this will block exhaust fluid, and release the TCC. The PCM monitors the difference in engine speed and the calculated transmission input shaft speed. With the TCC applied, the scan tool should display TCC slip speed of approximately -50 RPM to +50 RPM.

DTC 80 Will Set When:
No DTC 28, TCC slip speed is greater than 100 RPM, TCC indicates "ON," gear indicates 2, 3, or 4, trans range switch indicates "D3" or "D4," TP between 0% and 35%, TFT between 60°C and 100°C. All conditions must be met for 10 seconds.

Action Taken (PCM will default to):

- Inhibit TCC operation.
- Set line pressure to max (harsh shifts).
- Inhibit 4th gear if in hot mode.

DTC 80 will be stored in the PCM memory but will not turn "ON" the Malfunction Indicator Lamp (MIL).

DTC 80 Will Clear When:
The fault condition(s) no longer exist, and the ignition switch is cycled "OFF" then "ON."

Test Description: Number(s) below refer to circled number(s) on the diagnostic chart.

1. This test checks the indicated range signal to the actual selected range.

2. This test checks the torque converter for slippage while in a commanded locked-up state.

Diagnostic Aids:
- Check for poor connections at pass-thru connector.
- A faulty trans range pressure switch assembly may set DTC 80.