For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P2763 : Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control Circuit High Voltage
DTC P2764: Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control Circuit Low Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage
--- | --- | --- | ---
Ignition 1 Voltage | P0973, P0976, P2764 | P0973, P0976, P2764 | --
1-2 SS Valve Control | P0973 | P0973 | P0974
2-3 SS Valve Control | P0976 | P0976 | P0977
TCC PWM Valve Control | P2764 | P2764 | P2763

### Circuit/System 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 transmission control module (TCM) 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.

### Conditions for Running the DTC

The engine speed is 500 RPM for 5 seconds.

### Conditions for Setting the DTC

#### P2763

The TCM commands the solenoid ON and the voltage feedback remains high B+.

#### P2764

• | The TCM detects an open in the TCC PWM solenoid valve circuit when the TCC PWM is commanded ON.

• | The TCM detects a short to ground in the TCC PWM solenoid valve circuit when the TCC PWM is commanded ON.

### Action Taken When the DTC Sets

• | DTCs P2763 and P2764 are Type B DTCs.

• | The TCM commands maximum line pressure.

• | The TCM forces TCC OFF.

• | The TCM inhibits 4th gear if in Hot Mode.

• | The TCM freezes transmission adaptive functions.

### Conditions for Clearing the DTC

DTCs P2763 and P2764 are Type B DTCs.

### Reference Information

#### Schematic Reference

Automatic Transmission Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Transmission General Information

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Transmission Control Module Scan Tool Information

#### Special Tools

• | J 44152 Jumper Harness (20 Pins)

• | J 45681 Jumper Harness

### Circuit/System Verification

1. Ignition ON, engine OFF, observe the TCC Duty Cycle Sol. CKT Status parameter while commanding the TCC Control Solenoid to 90 percent and then back to 0 percent with a scan tool. The reading should display OK or Indeterminate.
2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

### Circuit/System Testing

Important: Additional DTCs may set when disconnecting the automatic transmission inline 20-way connector.

1. Ignition OFF, disconnect the automatic transmission (AT) inline 20-way connector at the transmission.
2. Install the J 45681 jumper harness, on the engine side of the AT inline 20-way connector.
3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal L and ground.

⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.

4. Connect a test lamp between the control circuit terminal U and the ignition circuit terminal L.
5. Command the TCC Control Solenoid to 90 percent and then back to 0 percent with a scan tool. The test lamp should turn ON when commanded to 90 percent and then turn OFF when 0 percent is commanded.

⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the TCM.

⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the TCM.

6. If all circuits test normal, test the automatic transmission internal wiring harness and the TCC PWM solenoid.

### Component Testing

1. Ignition OFF, disconnect the AT inline 20-way connector at the transmission.
2. Install the J 44152 jumper harness (20 pins), on the transmission side of the AT inline 20-way connector.
3. Test for 10-15 ohms of resistance between the control terminal U and the ignition terminal L of the transmission.

⇒ | If not within the specified range, test the circuits for a short to ground or an open/high resistance. If a circuit is shorted or open replace the internal transmission harness, if the circuits test normal, replace the TCC PWM solenoid.

4. Test for infinite resistance between each terminal and the transmission housing/case.

⇒ | If not the specified value, test the circuits for a short to ground or an open/high resistance. If a circuit is shorted replace the internal transmission harness, if the circuits test normal, replace the TCC PWM solenoid.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• | Torque Converter Clutch Pulse Width Modulation Solenoid, Torque Converter Clutch Solenoid, and Wiring Harness

• | Control Module References for TCM replacement, setup and reprogramming