C1091

C1091-ABS BRAKE LAMP CONTROL CIRCUIT HIGH





For a complete wiring diagram Refer to Diagram/Electrical. Electrical Diagrams


- When Monitored:

With the ignition on.

When Set:

When monitoring the Stop Lamp Inhibit Relay Control circuit the module detects a short to B+.







Diagnostic Test


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.

Turn the ignition on.

With the scan tool, record and erase DTCs.

Cycle the ignition switch from off to on.

With the scan tool, read DTCs.

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

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION diagnostic procedure. ABS Intermittent Condition Test
- Perform ABS VERIFICATION TEST ABS Verification Test


2. CHECK CONNECTOR/TERMINAL FOR DAMAGE


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

Turn the ignition off.

Inspect the Anti-Lock Brake Module harness connector, Stop Lamp Inhibit Relay harness connector.

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

Yes

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

No

- Go To 3


3. STOP LAMP INHIBIT RELAY





Turn the ignition off.

Measure the resistance of the Stop Lamp Inhibit Relay between (F500) Fused Ignition Switch Output circuit and (B45) Stop Lamp Inhibit Relay Control.

Is the resistance less then 5 ohms?

Yes

- Replace the Stop Lamp Inhibit Relay.
- Perform ABS VERIFICATION TEST. ABS Verification Test

No

- Go To 4


4. CHECK (B45) STOP LAMP INHIBIT RELAY CONTROL SHORTED TO VOLTAGE





Turn the ignition off.

Disconnect the Stop Lamp Inhibit Relay.

Using a 12-volt test light connected to ground, back probe the (B45) Stop Lamp Inhibit Relay Control circuit.

Does the test light illuminate brightly?

Yes

- Repair the short to voltage in the (B45) Brake Lamp Inhibit Relay Control circuit.
- Perform ABS VERIFICATION TEST. ABS Verification Test

No

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