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

### Typical Scan Tool Data

#### Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control Circuit Parameter Data

Circuit | Normal | Short to Ground | Open/High Resistance | Short to Voltage
--- | --- | --- | --- | ---
Operating Conditions: Engine running, normal operating temperature Parameter Normal Range: OK
1-2 Sol. CKT Status | OK | Open/Short to GND | Open/Short to GND | Short to Volts
2-3 Sol. CKT Status | OK | Open/Short to GND | Open/Short to GND | Short to Volts
TCC Duty Cycle CKT Status | OK | Open/Short to GND | Open/Short to GND | Short to Volts

### Circuit/System Description

The torque converter clutch pulse width modulated (TCC PWM) solenoid valve is a normally closed solenoid used to control the apply and release of the converter clutch. The TCM operates the solenoid with a negative duty cycle. When vehicle operating conditions are appropriate to apply the TCC, the TCM immediately increases the duty cycle to approximately 42 percent. The TCM then ramps the duty cycle to approximately 90 percent to achieve full TCC apply pressure. 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

#### P2763

• | The TCC is commanded ON.

• | The engine speed is greater than 500 RPM for 5 seconds.

#### P2764

The engine speed is greater than 500 RPM for 5 seconds.

### Conditions for Setting the DTC

#### P2763

The TCM detects a short to voltage on the TCC PWM solenoid valve control circuit for 4.4 seconds.

#### P2764

The TCM detects an open or short to ground on the TCC PWM solenoid valve control circuit for 4.4 seconds.

### Action Taken When the DTC Sets

#### P2763

• | DTC P2763 is a Type B DTC.

• | The TCM forces the TCC solenoid OFF.

• | The TCM inhibits TCC engagement.

• | The TCM inhibits 4th gear when in HOT mode.

• | The TCM commands maximum line pressure.

• | The TCM freezes transmission adaptive functions.

#### P2764

• | DTC P2764 is a Type B DTC.

• | The TCM forces the TCC solenoid OFF.

• | The TCM inhibits TCC engagement.

• | The TCM inhibits 4th gear when in HOT mode.

• | The TCM commands maximum line pressure.

• | 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

Electronic Component Description for torque converter clutch pulse width modulated solenoid valve 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

Control Module References for scan tool information

#### Special Tools

J 44152 Jumper Harness (20 pins)

### 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 44152 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 E 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 T and the ignition circuit terminal E.
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 internal transmission wiring harness assembly 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 44152 on the transmission side of the AT inline 20-way connector.
3. Test for 10-15 ohms of resistance between the control terminal T and the ignition terminal E 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 wiring harness assembly, 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 wiring harness assembly, if the circuits test normal, replace the TCC PWM solenoid.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• | Wiring Harness Replacement

• | Torque Converter Clutch Pulse Width Modulation Solenoid Replacement

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