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 Descriptor

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
--- | --- | --- | ---
TCC PWM Solenoid | P2764 | P2764 | P2763

### Circuit/System Description

The transmission control module (TCM) provides voltage to the torque converter clutch pulse width modulated (TCC PWM) solenoid valve through high side driver 2 (HSD2). The TCM controls the ON and OFF time of the solenoid by providing a ground through the output driver module (ODM). The TCM uses a PWM duty cycle, in order to control application and release of the TCC. When the solenoid is commanded OFF, the TCM senses high voltage. When the solenoid is commanded ON, the TCM senses low voltage.

### Conditions for Running the DTC

• | The engine run time is greater than 5 seconds.

• | HSD2 is commanded ON.

### Conditions for Setting the DTC

#### P2763

The TCM detects a short to voltage in the TCC PWM solenoid valve circuit when the PWM duty cycle is 45 percent or greater for 4.3 seconds.

#### P2764

The following conditions occur for 4.3 seconds:

• | The TCM detects an open in the TCC PWM solenoid valve circuit when the PWM duty cycle is 20 percent or greater.

• | The TCM detects a short to ground in the TCC PWM solenoid valve circuit when the PWM duty cycle is 20-50 percent.

### Action Taken When the DTC Sets

#### P2763

• | DTC P2763 is a Type B DTC.

• | The TCM inhibits TCC.

• | The TCM inhibits fifth gear if the transmission is in Hot Mode.

• | The TCM freezes transmission adaptive functions.

#### P2764

• | DTC P2764 is a Type B DTC.

• | The TCM turns off power to all solenoids.

• | The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.

• | The TCM commands maximum line pressure.

• | The TCM freezes transmission adaptive functions.

### Conditions for Clearing the DTC

DTC 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 Description

#### 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 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 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 17 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 20 and the ignition circuit terminal 17.
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 automatic transmission (AT) inline 20-way connector at the transmission.
2. Install the J 45681 on the transmission side of the AT inline 20-way connector.
3. Test for 10-13.6 ohms of resistance between the control terminal 20 and the ignition terminal 17 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 Solenoid Replacement

• | Transmission Internal Electrical Harness Replacement

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