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 P0719: Brake Switch Circuit Low Input

### Circuit/System Description

The TCC brake switch indicates brake pedal status to Transmission Control Module (TCM). The TCC brake switch indicates brake pedal applied or released. The normally-closed switch indicates the battery supplies voltage to Transmission Control Module (TCM). Apply the brake pedal to active the TCC brake switch, disconnect the PCM the TCM receives 0 volts at the TCC brake switch input, the TCM turns OFF the torque converter clutch pulse width modulation solenoid valve.

DTC P0719 can be set if a disconnected parking brake switch (indicates the pedal is depressed) is detected by the TCM in a series of accelerations. DTC P0719 is a type C DTC.

### Conditions for Running the DTC

• | DTC P0719 failed this ignition cycle.

• | Active the ignition voltage.

• | DTCs P0722, P0723 are not set.

### Conditions for Setting the DTC

The TCC brake switch indicates a continuous disconnecting for more than 15 minutes, the following conditions occur 8 times continuously.

• | The vehicle speed is less than 8 km/h (5 mph)

• | Then the vehicle speed accelerates to 32 km/h (20 mph) in 4 seconds;

• | At last, the vehicle speed keeps at 32 km/h in 6 seconds greater than (20 mph

### Action Taken When the DTC Sets

• | DTC P0719 is a type C DTC.

• | The PCM disregards the TCC brake switch for TCC scheduling when all of the following conditions are met

- | The TP angle is greater than 6 percent.

- | The vehicle speed is greater than 60 km/h (37 mph).

- | The TP angle was previously greater than 12% while the vehicle speed was greater than 68 km/h (42 mph).

- | The TCC brake switch has not indicated OFF for more than 2 seconds this trip.

### Conditions for Clearing the DTC

DTC P0719 is a type C DTC.

### Diagnostic Aids

• | Inspect the controller, components and all other circuit attaching points for an intermittent.

• | Inspect the circuit wiring for an intermittent.

### Reference Information

#### Schematic Reference

Automatic Transmission Controls Schematics

#### Connector End View Reference

• | Automatic Transmission Inline 16-Way Connector End View

• | Automatic Transmission Internal Connector End Views

• | Automatic Transmission Related Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

• | Diagnostic Trouble Code (DTC) Type Definitions

• | Diagnostic Trouble Code (DTC) List/Type

#### Scan Tool Reference

• | Scan Tool Output Controls

• | Scan Tool Data List

• | Scan Tool Data Definitions

#### Special Tools

J 35616 GM-Approved Terminal Test Kit Circuit/System Testing

### Circuit/System Testing

1. Install the scan tool, turn the ignition switch to ON position.

Important: Before clearing the DTCs, use the scan tool to record the Failure Records; use the Clear Info. function to erase the Failure Records from the TCM.

2. Record the DTC Failure Records,
3. Clearing Diagnostic Trouble Codes,
4. Select TCC Brake Switch on the scan tool,
5. Disconnect the brake switch connector from the brake switch.
6. Connect a test lamp from the ignition 1 voltage supply circuit in the brake switch connector to ground. The test lamp should be illuminated normally.

⇒ | If the test lamp is not illuminated, inspect the ignition 1 voltage supply circuit for a short to voltage.

⇒ | If no concerns were found, test the brake switch for a short to ground, if the circuits/connectors test normal, replace the transmission control module (TCM).

⇒ | If no concerns were found, test the ignition 1 voltage circuit of the brake switch for an open, if the circuits/connectors test normal, replace the TCM.

7. Connect a fuse between the ignition 1 voltage supply circuit and the stop lamp switch connector signal circuit. Observe if the Status of the TCC Brake Switch displayed on the scan tool change from OPEN to CLOSED.

⇒ | If it changes to CLOSED, replace the brake switch.

⇒ | If there is not change, test the brake switch signal circuit for an open. If the circuit/connection test is normal, replace the TCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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