P0742

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The PCM energizes the TCC Solenoid Valve by creating a ground path on circuit 422. When grounded (energized) by the PCM, the TCC Solenoid Valve stops converter signal oil exhaust. Converter signal oil pressure will increase. Increased converter signal oil pressure will move the TCC valve. The TCC Solenoid Valve will de-energize when the PCM no longer provides a ground path. When the TCC Solenoid Valve is de-energized, the valve will release fluid and release the TCC.

If the PCM detects a low torque converter slip when the TCC is OFF, then DTC P0742 sets. DTC P0742 is a type A DTC.


CONDITIONS FOR SETTING THE DTC

- No DTCs P0122 or P0123

- No Vehicle Speed Sensor (VSS) DTC P0502

- No TFP Valve Position Switch DTC P1810

- No TCC Pulse Width Modulation (PWM) Solenoid Valve DTC P1860

- No TCC Solenoid Valve DTC P1864

- The Throttle Position (TP) angle is greater than 15%.

- The engine speed is greater than 400 RPM for 8 seconds and not in fuel cutoff.

- The engine vacuum is 0-106 kPa.

- The engine torque is 40-400 lb. ft.

- The commanded gear is not 1st.

- The gear range is D4, D3, or D2.

- The TCC is commanded OFF.

- The TCC slip speed is 2030 RPM.

- All conditions are met for 5 seconds.

ACTION TAKEN WHEN THE DTC SETS

- The PCM freezes shift adapts from being updated.

- The PCM illuminates the Malfunction Indicator Lamp (MIL).

CONDITIONS FOR CLEARING THE MIL/DTC

- The PCM turns OFF the MIL after three consecutive ignition cycles without a failure reported.

- A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.

- The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

DIAGNOSTIC AIDS

- The TCC may mechanically stick ON with the parking brake applied and any gear range selected. In this case, the TCC fluid mechanically applies the TCC. Mechanically applying the TCC may cause an engine stall.

- A stuck TP sensor at greater than 15% will set this code.

TEST DESCRIPTION

The numbers below refer to the step numbers on the diagnostic chart.

3. This Step tests the TCC for a mechanical malfunction. When the PCM commands the TCC Solenoid Valve OFF, the slip speed should increase.