Valve Power Feed Failure

VALVE POWER FEED FAILURE





For a complete wiring diagram Consult Diagrams/Electrical

- When Monitored:
Ignition on. The CAB monitors its internal microprocessors for correct operation.

- Set Condition:
If the CAB detects an internal fault, the DTC is set.





Diagnostic Test

1. VALVE POWER FEED FAILURE DTC PRESENT
Turn the ignition on.
With the Scan Tool, read DTCs.
With the Scan Tool, erase DTCs.
Turn the ignition off.
Turn the ignition on.
With the Scan Tool, read DTCs.
Does the Scan Tool display VALVE POWER FEED FAILURE?

Yes

- Go To2

No

- Go To10

2. ABS VALVE FUSE OPEN
Turn the ignition off.
Remove and Inspect the ABS Valve fuse.
Is the ABS Valve fuse open?

Yes

- Go To3

No

- Go To6

3. ABS VALVE FUSED B(+) CIRCUIT INTERMITTENT SHORT TO GROUND
Turn the ignition off.
Visually inspect the ABS Valve Fused B(+) circuit in the wiring harness. Look for any sign of an intermittent short to ground.
Is the wiring harness OK?

Yes

- Go To4

No

- Repair the ABS Valve Fused B(+) circuit for a short to ground.
- Perform ABS VERIFICATION TEST.ABS Verification Test

4. ABS VALVE FUSED B(+) CIRCUIT SHORT TO GROUND
Turn the ignition off.
Disconnect the CAB harness connector.

NOTE: Check connector - Clean/repair as necessary.

Using a test light connected to 12 volts, probe the ABS Valve Fused B(+) circuit fuse terminal.
Did the test light illuminate?

Yes

- Repair the ABS Valve Fused B(+) circuit for a short to ground.
- Perform ABS VERIFICATION TEST.ABS Verification Test

No

- Go To5

5. CAB - ABS VALVE FUSED B(+) CIRCUIT SHORT TO GROUND
Turn the ignition off.
Reconnect the CAB harness connector.

NOTE: The CAB harness connector must be reconnected for the results of this test to be valid.

Using a test light connected to 12 volts, probe the ABS Valve Fused B(+) circuit fuse terminal.
Did the test light illuminate?

Yes

- Replace the Anti-Lock Brake Controller (CAB).
- Perform ABS VERIFICATION TEST.ABS Verification Test

No

- Replace the ABS Valve Fused B(+) fuse. If the fuse is open make sure to check for a short to ground.
- Perform ABS VERIFICATION TEST.ABS Verification Test

6. DAMAGED CAB/CAB HARNESS CONNECTOR
Turn the ignition off.
Disconnect the CAB harness connector.
Inspect the CAB and CAB harness connector for damage.
Is there any broken, bent, pushed out, corroded or spread terminals?

Yes

- Repair as necessary.
- Perform ABS VERIFICATION TEST.ABS Verification Test

No

- Go To7

7. B(+) SUPPLY CIRCUIT OPEN




Turn the ignition off.
Using a 12-volt test light connected to ground, probe the B(+) supply at the ABS Valve fuse terminal.
Did the test light illuminate?

Yes

- Go To8

No

- Repair the ABS Valve Fused B(+) supply circuit for an open.
- Perform ABS VERIFICATION TEST.ABS Verification Test

8. ABS VALVE FUSED B(+) CIRCUIT OPEN




Reinstall the ABS Valve fuse.
Disconnect the CAB harness connector.
Using a 12-volt test light connected to ground, probe the ABS Valve Fused B(+) circuit at the CAB harness connector.
Did the test light illuminate?

Yes

- Go To9

No

- Repair the ABS Valve Fused B(+) circuit for an open.
- Perform ABS VERIFICATION TEST.ABS Verification Test

9. CAB - GROUND CIRCUIT OPEN




Turn the ignition off.
Using a 12-volt test light connected to 12-volts, probe the ground circuits at the CAB harness connector.
Did the test light illuminate?

Yes

- Replace the Anti-Lock Brake Controller (CAB).
- Perform ABS VERIFICATION TEST.ABS Verification Test

No

- Repair the CAB Ground circuit for an open.
- Perform ABS VERIFICATION TEST.ABS Verification Test

10. WIRING HARNESS INSPECTION
Turn the ignition off.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.
Visually inspect the related wire harness connectors. Look for broken, bent, pushed out, or corroded terminals.
Refer to any Hotline letters or Technical Service Bulletins that may apply.
Were any problems found?

Yes

- Repair as necessary.
- Perform ABS VERIFICATION TEST.ABS Verification Test

No

- Test Complete.