P0742

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Torque Converter Clutch Solenoid Valve (TCC Sol. Valve) is a normally-open exhaust valve that is used with the Torque Converter Clutch Pulse Width Modulation Solenoid Valve (TCC PWM Sol. Valve) in order to control fluid acting on the converter clutch apply valve. The TCC Sol. Valve attaches to the transmission case assembly extending into the pump cover. When grounded (energized) by the Vehicle Control Module (VCM), the TCC Sol. Valve stops converter signal oil from exhausting. This causes converter signal oil pressure to increase and move the converter clutch apply valve against spring force and into the apply position. In this position, release fluid is open to an exhaust port and converter feed fluid fills the apply fluid circuit. The converter feed fluid applies the TCC. When the VCM no longer provides a ground path, the TCC Sol. Valve de-energizes and apply fluid exhausts, releasing the TCC.

When the VCM detects low torque converter slip when the TCC is commanded OFF, then DTC P0742 sets. DTC P0742 is a type B DTC.


CONDITIONS FOR SETTING THE DTC

DTC P0742 sets if the following conditions occur twice per ignition cycle, two consecutive times.

^ No Manifold Absolute Pressure (MAP) Sensor DTCs P0107 or P0108.

^ No Throttle Position (TP) Sensor DTCs P0122 or P0123.

^ No Vehicle Speed Sensor (VSS) Assy. DTCs P0502 or P0503.

^ No TCC Sol. Valve DTC P0740.

^ No Transmission Fluid Pressure (TFP) Val. Position Sw. DTC P1810.

^ No TCC PWM Sol. Valve DTC P1860.

^ The TP angle is 17-45%.

^ The engine speed is greater than 450 RPM for 5 seconds.

^ Not in fuel cutoff.

^ The engine speed is 1000-3000 RPM.

^ The speed ratio is 0.64 to 1.35.

^ The vehicle speed is 24-80 km/h (15-50 mph).

^ No gear range change within 5 seconds.

^ The engine vacuum is 0-105 kPa.

^ The engine torque is 50-400 lb. ft.

^ The commanded gear is not 1st.

^ The gear range is D4.

^ The TCC is commanded OFF.

^ The TCC slip speed is -20 to +20 RPM.

^ All conditions met for 5 seconds.


ACTION TAKEN WHEN THE DTC SETS

^ The VCM illuminates the Malfunction Indicator Lamp (MIL).

^ The VCM freezes shift adapts from being updated.

^ DTC P0742 stores in VCM history.


CONDITIONS FOR CLEARING THE MIL/DTC

^ The VCM turns OFF the MIL after three consecutive trips without a failure reported.

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

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

DIAGNOSTIC AIDS

^ The TCC fluid will mechanically apply the TCC, possibly causing an engine stall, under the following conditions:

- The TCC is mechanically stuck ON.

- The parking brake is applied.

- Any gear range is selected.

^ A stuck TP Sensor may set DTC P0742.


TEST DESCRIPTION

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

3. This step tests the mechanical state of the TCC. When the VCM commands the TCC Sol. Valve OFF, the slip speed should increase.