Brake Light and Brake Pedal Switches, Checking

Brake Light and Brake Pedal Switches, Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• The Brake Light Switch (F) fuse OK.

• The Brake Pedal Switch (F47) fuse OK.

• Battery voltage at least 12.5 volts.

• All electrical consumers such as, lights and rear window defroster, switched off.

• Vehicles with automatic transmission, shift selector lever into position " P" or "N".

• A/C switched off.

• Ground (GND) connections between engine/transmission/chassis OK.

• Ignition switched off.

Test procedure

- Perform a preliminary check to verify the customers complaint. Refer to => [ General Diagnosis ] General Diagnosis.

Start diagnosis

- Remove the drivers side storage compartment.

Checking internal resistance

- Disconnect the Brake Light Switch (F)/Brake Pedal Switch (F47) electrical harness connector.

- Using a Multimeter, check the Brake Pedal Switch (F47) terminals 1 to 4 for a internal short.





Specified value: infinite (infinity).

If the specified value was not obtained:

- Replace the Brake Light Switch (F)/Brake Pedal Switch (F47).

If the specified value was obtained:

- Using a Multimeter, check the Brake Pedal Switch (F47) terminals 1 to 4 for resistance.





- Press the brake pedal switch plunger in.

Specified value: approx. 0 ohms

If the specified value was obtained:

- Check the voltage supply of the Brake Light Switch (F)/Brake Pedal Switch (F47).

If the specified value was not obtained:

- Replace the Brake Light Switch (F)/Brake Pedal Switch (F47).

Checking voltage supply

- Switch the ignition on.

- Using a Multimeter, check the Brake Pedal Switch (F47) electrical harness connector terminal 1 to Ground (GND).





Specified value: battery voltage.

If the specified value was not obtained:

- Using a Multimeter, check the Brake Pedal Switch (F47) electrical harness connector terminal 3 to Ground (GND).

Specified value: battery voltage.

- Switch the ignition off.

If the specified value was not obtained:

- Check the wiring.

If the specified value was obtained:

- Replace the Brake Light Switch (F)/Brake Pedal Switch (F47).

Checking wiring

If the manufacturers test box is being used. Perform the following step.

- Install the test box. Refer to Fuel Injection and Ignition Repair Information.

If the manufacturers test box is not being used. Perform the following step.

- Remove the Engine Control Module (ECM) (J623 ). Refer to => [ ECM, Removing and Installing ] ECM, Removing and Installing.

- Using a Multimeter, check the Brake Light Switch (F)/Brake Pedal Switch ( F47) electrical harness connector to the Engine Control Module (ECM) (J623) electrical harness connector T94 for open an circuit.









Specified value: 1.5 ohms Max.

If the specified value was not obtained:

- Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).

- Check the wiring connection for damage, corrosion, lose or broken terminals.

- If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and voltage supply was not OK:

- Replace the Engine Control Module (ECM) (J623 ). Refer to => [ ECM, Removing and Installing ] ECM, Removing and Installing.

- Install the drivers side storage compartment. Refer to Fuel Injection and Ignition Repair Information.

Final procedures

After the repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.

2. If necessary, erase the DTC memory. => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.

3. If the DTC memory was erased, generate readiness code. => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.

- End of diagnosis.