Troubleshooting

Troubleshooting BCM-C004064

Checking the brake control module (BCM) and the brake light switch connector








- Ignition off
- Check the connectors of the brake control module (BCM) and the brake light switch for contact resistance and oxidation.
- Reinstall the components, reconnect the connectors etc.
- Ignition on
- Read the status of the brake light switch.
Depress the brake pedal and release it. The value should change between OFF and ON.
If the value changes, the malfunction was caused by poor contact in the brake control module (BCM) or brake light switch connector.

Other information
- For information on brake control module (BCM) connector removal: Connecting the breakout box, brake control module (BCM), B6324S5 Connecting The Breakout Box
- Checking wiring and terminals Checking Wiring And Terminals





Does the value change?

Yes - FAULT FOUND

No - Checking fuses, wiring and sensors

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Checking fuses, wiring and sensors
Check that the brake light switch fuse in the engine compartment relay/fuse box is intact.
Check the cable between brake light switch terminal #1 and the fuse in the engine compartment relay/fuse box as well as between brake light switch terminal #5 and the connector for open circuit, short-circuit to ground and short-circuit to voltage.
Check the cable between the connector and central electronic module (CEM) terminal #B4 and between the connector and engine electronic module (ECM) terminal #B26 for open circuit, short-circuit to ground and short-circuit to voltage.

Hint: Check the brake light switch by measuring the resistance between terminals #1 and #5 on the brake light switch. Resistance should be infinite when the brake light switch is activated and 0 ohms when the brake light switch is not activated.

Remedy as necessary.

Other information
- Connecting the breakout box, brake control module (BCM), B6324S5 Connecting The Breakout Box
- To connect the breakout box to the Engine control module (ECM), see: Connecting the breakout box, B6324S5 Connecting The Breakout Box, Engine Control Module (ECM)
- For connection of the breakout box to the central electronic module (CEM): Connecting the breakout box Connecting The Breakout Box, Central Electronic Module (CEM)
- Stop lamp switch, replacing Service and Repair
- Checking wiring and terminals Checking Wiring And Terminals
- For information on relay and fuse locations, see the wiring diagram.





Was a malfunction detected?

Yes - Verification

No - No Fault Found

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Verification




- Ignition off
- Reinstall the components, reconnect the connectors etc.
- Ignition on
- Read the status of the brake light switch.
Depress the brake pedal and release it. The value should change between OFF and ON.





Does the value change?

Yes - FAULT FOUND

No - Troubleshooting information

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Troubleshooting information

Attempt New Test - Checking the brake control module (BCM) and the brake light switch connector

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