Mechanical Fault

Mechanical fault

Checking the operation of the pump motor








- Ignition off
- Check the connector on the brake control module (BCM). Check for contact resistance. Check for oxidation
- Reconnect the components, connectors, etc.
- Ignition on
- Activate the pump motor.
Check that the pump motor starts and operates normally.
If the pump motor starts and seems to operate normally, the cause of the fault was contact resistance and oxidation in the control module connector.

Other information
- Connecting the breakout box, B5254T7 Connecting the Breakout Box, Brake Control Module (BCM)
- Checking wiring and terminals Checking Wiring and Terminals





Is the pump OK?

Yes - FAULT FOUND

No - Checking the wiring and component

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Checking the wiring and component




- Ignition off.
Check the wiring between brake control module (BCM) terminal #1 (#A1) and the battery. Check for an open-circuit. Check for a short-circuit to ground.
Check if the fuse for the brake system in the integrated relay/fusebox in the engine compartment is damaged. If the fuse is damaged, check the cable between the fuse and brake control module (BCM) terminal #1 (#A1). Check for a short-circuit to ground. Then replace the fuse.
Check the pump motor circuit by connecting an ohmmeter between pump motor connector terminal #2 and ground. The ohmmeter should read infinite resistance.
Remedy as necessary.

Other information
- Connecting the breakout box, B5254T7 Connecting the Breakout Box, Brake Control Module (BCM)
- Hydraulic unit brake system, B5254T7 Service and Repair
- Checking wiring and terminals Checking Wiring and Terminals
- For further information about the fuses and relays, see the Wiring Diagram.









Was a fault detected?

Yes - Verification

No - Fault-tracing information

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Verification




Verification

Hint: After carrying out the repair, check that the fault has been remedied.








- Ignition off
- Reconnect the components, connectors, etc.
- Ignition on
- Activate the pump motor.
Check that the pump motor starts and operates normally.





Is the pump OK?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFIED - FAULT FOUND

VERIFICATION FAILED - Fault-tracing information

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Fault-tracing information




Information

Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Do you want to exit fault-tracing?

Yes - Exit fault-tracing

No - Attempt New Test

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Attempt New Test - Checking the operation of the pump motor

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