P0742

CIRCUIT DESCRIPTION

The Powertrain Control Module (PCM) controls the Torque Converter Clutch Solenoid Valve (TCC Sol. Valve) pulse width modulation (PWM). The solenoid controls the hydraulic fluid for TCC apply and release. When the vehicle is accelerating, the PCM commands the TCC to be disengaged.

If the PCM detects a TCC slip from -5 to +80 RPM, when the TCC is commanded OFF, then DTC P0742 sets. DTC P0742 is a Type B DTC.

CONDITIONS FOR SETTING THE DTC

^ No MAF DTCs P0101, P0102, or P0103 are set.
^ No Throttle Position (TP) sensor DTCs P0121, P0122, or P0123 are set.
^ No Vehicle Speed (VSS) sensor DTCs P0502 or P0503 are set.
^ No Automatic Transmission Input Speed Sensor (A/T ISS) DTCs P0716 or P0717 are set.
^ No TCC Stuck OFF DTC P0741 is set.
^ No Automatic Transmission Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.) DTC P1810 is set.
^ No TCC PWM Sol. Valve DTC P1860 is set.
^ The engine has been running for more than 5 seconds.
^ The PCM commands the TCC Sol. Valve OFF.
^ The TFP Val. Position Sw. indicates D4.
^ The transmission gear ratio indicates 2nd, 3rd or 4th gear.
^ The throttle angle is greater than 11.8°.
^ The delivered torque is 135-270 Nm (100-200 lb ft).

Fault Criteria: The slip speed is -5 to +80 RPM for 6 seconds (Slip speed equals engine speed minus transmission input shaft speed).

ACTION TAKEN WHEN THE DTC SETS

^ The PCM illuminates the Malfunction Indicator Lamp (MIL) after two consecutive trips with a reported failure.
^ SERVICE ENGINE SOON, SERVICE TRANSMISSION displays on the Driver Information Center (DIC).
^ The PCM inhibits Torque Converter Clutch.
^ The PCM inhibits 4th gear if the transmission is in hot mode.

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

Inspect the transmission fluid for sediment or debris.

TEST DESCRIPTION

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

2. This step verified that the PCM commanded the TCC Sol. Valve OFF and the slip speed is -5 to +80 RPM for more than 6 seconds.
3. This step inspects and repairs the components that caused the DTC to set.