C1091

C1091-ABS BRAKE LAMP CONTROL CIRCUIT HIGH





For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
With the ignition on.

- When Set:
When monitoring the Brake Lamp Activation Relay Control circuit the module detects a short to B+.





1. CHECK FOR DTC C1091-ABS BRAKE LAMP CONTROL CIRCUIT HIGH

NOTE: This DTC must be active for the results of this test to be valid.

1. Turn the ignition on.
2. With the scan tool, record and erase the DTCs.
3. Start the Engine.
4. Apply brake pedal firmly with at least 80 bar (1160 psi.).
5. With the scan tool, read the DTCs.

Does the scan tool display: C1091-ABS BRAKE LAMP CONTROL CIRCUIT HIGH?

Yes

- Go To 2

No

- Perform the ABS INTERMITTENT CONDITION TEST. ABS Intermittent Condition Test.

2. CHECK CONNECTOR/TERMINAL FOR DAMAGE

NOTE: Check all terminals for broken, bent, pushed out, or corroded terminals.

1. Turn the ignition off.
2. Inspect the Anti-Lock Brake Module harness connector and the Brake Lamp Activation Relay harness connector.

Is the Anti-Lock Brake Module or any of the connectors/terminals damaged?

Yes

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

No

- Go To 3

3. CHECK (B221) BRAKE LAMP ACTIVATION RELAY CONTROL SHORTED TO VOLTAGE




1. Turn the ignition off.
2. Disconnect the Anti-Lock Brake Module
3. Disconnect the Brake Lamp Activation Relay.
4. Turn the ignition on.
5. Using a 12-volt test light connected to ground, probe the (B221) Brake Lamp Activation Relay Control Circuit at the Brake Lamp Activation Relay harness connector.

Does the test light illuminate brightly?

Yes

- Repair the short to voltage in the (B221) Brake Lamp Activation Relay Control circuit.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

No

- Go To 4

4. BRAKE LAMP ACTIVATION RELAY




1. Turn the ignition off.
2. Measure the resistance across the relay between the (B221) Brake Lamp Activation Relay Control Circuit and the (F943) Fused Ignition switch Output.

Is the resistance 75 - 95 Ohms?

Yes

- Replace the Anti-Lock Brake Module.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.

No

- Replace the Brake Lamp Activation Relay.
- Perform the ABS VERIFICATION TEST. ABS Verification Test.