Operation CHARM: Car repair manuals for everyone.

Checking the Power Supply, Brake Control Module






Checking the power supply, brake control module

Checking the 15-supply to the control module








- The breakout box connected
- Control module disconnected.
- Ignition on.
Check the 15-supply by measuring the voltage between terminal #4 (#A4) and ground terminals #16 (#A16) and #46 (#A46). The voltmeter should read battery voltage.
Check that the fuse for the circuit is intact if the voltage is incorrect.
If the fuse is blown, check the cable between brake control module terminal #4 (#A4) and the fuse. Check for a short-circuit to ground.
If the fuse is intact, check the cable between brake control module terminal #4 (#A4) and the fuse. Check for an open-circuit.
If no fault is found in the cable between brake control module terminal #4 (#A4) and the fuse, check the cable between the fuse and the ignition switch.

Other information
- To connect the breakout box, see Connecting the breakout box, brake control module (BCM) Connecting the Breakout Box, Brake Control Module (BCM)
- For further information about the fuses and relays, see the Wiring Diagram.









Was a fault detected?

OK - Verification

Not OK - Checking the 30-supply (valves) to the control module

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Checking the 30-supply (valves) to the control module




- The breakout box connected
- Ignition on.
Check the voltage between breakout box terminals #16 and #32 and between terminals #32 and #46. The voltmeter should read battery voltage.
Check that the fuse for the circuit is intact if the voltage is incorrect.
If the fuse is blown, check the cable between brake control module terminal #32 (#A32) and the fuse. Check for a short-circuit to ground.
If the fuse is intact, check the cable between brake control module terminal #32 (#A32) and the fuse. Check for an open-circuit.
Remedy as necessary









Was a fault detected?

Yes - Verification

No - Fault-tracing information

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Verification

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








- Ignition off
- Reconnect the connectors, reinstall components etc.
- Ignition on.
The ABS warning lamp lights when the ignition is switched on.
Check that the warning lamp goes out after approximately 2 seconds.

Note! The warning lamp will not go out if a fault has been stored in the control module.





Does the warning lamp go out after 2seconds?

Yes - Fault Found

No - Fault-tracing information

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Fault-tracing information




Information

Fault-tracing information
The fault should be diagnosed and remedied. Since this is not the case the fault-tracing process has failed.
Complete the fault-tracing for those fault or try again.

Do you want to terminate fault-tracing at this time?

Yes - FAULT-TRACING FAILED

No - Attempt New Test

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Attempt New Test - Checking the 15-supply to the control module

FAULT-TRACING FAILED - FAULT-TRACING FAILED

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