P2764
DTC P2764 (4.2L)
Circuit Description
The torque converter clutch pulse width modulation (TCC PWM) solenoid valve controls the fluid acting on the converter clutch valve. The converter clutch valve controls the TCC application and release. The solenoid attaches to the control valve body within the transmission. The solenoid receives voltage through the ignition voltage circuit. The powertrain control module (PCM) controls the solenoid by providing a ground path on the TCC PWM solenoid valve control circuit. Current flows through the solenoid coil according to the duty cycle, percentage of ON and OFF time. The TCC PWM solenoid valve provides a smooth engagement of the TCC by operating during a duty cycle percent of ON time.
When the PCM detects a continuous open or short to ground in the TCC PWM solenoid valve control circuit, then DTC P2764 sets. DTC P2764 is a type B DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P2764 Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control Circuit Low Voltage
Conditions for Running the DTC
- The system voltage is 8-18 volts.
- The engine speed is 475 RPM for 5 seconds.
Conditions for Setting the DTC
DTC P2764 sets when either of the following conditions occurs for 5 seconds:
- The PCM detects an open in the TCC PWM shift solenoid valve circuit when the TCC PWM is commanded ON.
- The PCM detects a short to ground in the TCC PWM shift solenoid valve circuit when the TCC PWM is commanded ON.
Action Taken When the DTC Sets
- The PCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
- The PCM commands maximum line pressure.
- The PCM inhibits TCC engagement.
- The PCM inhibits 4th gear if in hot mode.
- The PCM freezes transmission adaptive functions.
- The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
- The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Failure Records.
- The PCM stores DTC P2764 in PCM history.
Conditions for Clearing the DTC
- The engine control module (ECM) turns OFF the MIL after the third consecutive drive trip in which the PCM does not send a MIL illumination request.
- A scan tool can clear the DTC.
- The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring.
- The PCM cancels the default actions when the ignition is OFF long enough in order to power down the PCM.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
4. This step tests for voltage to the solenoid.
5. This step tests the ability of the PCM and wiring to control the ground circuit.
7. This step tests the resistance of the TCC PWM solenoid valve and the automatic transmission (AT) wiring harness.
