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 provide an overview of each diagnostic category.

### DTC Descriptors

DTC C0293 01: Park Brake Switch Control Short to Battery
DTC C0293 06: Park Brake Switch Control Low Voltage/Open
DTC C0293 08: Park Brake Switch Control Performance-Signal Invalid

### Circuit/System Description

The electric parking brake control module has an internal motor, apply actuator, release actuator, and temperature sensor. The electric parking brake control module also contains the logic for applying and releasing the parking brake when commanded by the electric parking brake switch. When the electric parking brake control module receives a signal from the switch the internal circuit board temperature is checked to verify it is within operating range before the control module performs the requested operation.

### Conditions for Running the DTC

Ignition OFF, ACCESSORY, or RUN mode.

### Conditions for Setting the DTC

The electric parking brake control module detects a short to battery, short to ground, open circuit, or an internal parking brake switch control malfunction.

### Action Taken When the DTC Sets

• | The electric parking brake is disabled.

• | A message and/or a warning indicator may be displayed.

### Conditions for Clearing the DTC

• | The electric parking brake control module clears the history DTC when a current DTC is not detected in 40 ignition cycles.

• | The condition for the DTC is no longer present.

### Reference Information

#### Schematic Reference

Park Brake System Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Electronic Parking Brake Control Module Description

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Test

#### C0293 01 or C0293 06

1. Ignition OFF, disconnect the harness at the S91 Electric Parking Brake Switch.
2. Test for less than 5 Ω between the low reference circuit terminal listed below and ground:

• | Terminal 4

• | Terminal 5

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K83 Electric Parking Brake Control Module.

3. Ignition ON, verify a test lamp does not illuminate between the low reference circuit terminal listed below and ground:

• | Terminal 4

• | Terminal 5

⇒ | If the test lamp does illuminate, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the K83 Electric Parking Brake Control Module.

4. Test for 5 V between the 5 V circuit terminal listed below and ground:

• | Terminal 3

• | Terminal 7

⇒ | If greater than the specified range, test the 5 V circuit for a short to voltage. If the circuit tests normal, replace the K83 Electric Parking Brake Control Module.

5. Test for infinite resistance between the 5 V circuit terminal listed below and ground:

• | Terminal 3

• | Terminal 7

⇒ | If less than the specified range, test the 5 V circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K83 Electric Parking Brake Control Module.

6. Test for infinite resistance between the 12 V circuit terminal listed below and ground:

• | Terminal 1

• | Terminal 2

⇒ | If less than the specified range, test the 12 V circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K83 Electric Parking Brake Control Module.

7. If all circuits test normal, test or replace the S91 Electric Parking Brake Switch.

#### C0293 08

Remove the EPB fuse and reinstall. Verify DTC C0293 08 is not set.

⇒ | If DTC C0293 08 is set, replace the S91 Electric Parking Brake Switch.

### Component Testing

1. Ignition OFF, disconnect the harness connector at the S91 Electric Parking Brake Switch.
2. Test for infinite resistance between terminal 2 and terminal 3.

⇒ | If less than the specified range, replace the S91 Electric Parking Brake Switch.

3. Test for infinite resistance between terminal 2 and terminal 5.

⇒ | If less than the specified range, replace the S91 Electric Parking Brake Switch.

4. Test for infinite resistance between terminal 1 and terminal 4.

⇒ | If less than the specified range, replace the S91 Electric Parking Brake Switch.

5. Test for infinite resistance between terminal 1 and terminal 7.

⇒ | If less than the specified range, replace the S91 Electric Parking Brake Switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Electronic Parking Brake Control Module Replacement

• | Parking Brake Actuator Switch Replacement

• | Control Module References for electric parking brake control module replacement, setup, and programming