Diagnostic Routine K

Diagnostic Routine K

Diagnostic Overview

The Brake Warning Indicator is Never On

Refer to Wiring Diagram Set 60 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

REFER to Brake Warning Indicator , REFER to Park Position Detect Switch and REFER to Brake Fluid Level Switch .

Visual Inspection and Diagnostic Pre-checks

Inspect the brake fluid level switch for signs of any external damage. Inspect the brake fluid level switch wiring for signs of a pinched harness causing the an open circuit.

Pinpoint Test

1. CHECK THE BRAKE WARNING INDICATOR USING THE DEALER TEST MODE

1. Ignition OFF.

2. Enter the Dealer Test Mode. REFER to Dealer Test Mode .

3. Scroll to LED test.

4. Monitor the brake warning indicator.

Does the brake warning indicator illuminate?







2. DETERMINE IF THE BRAKE WARNING INDICATOR OPERATES WITH THE PARKING BRAKE APPLIED

1. Ignition ON.

2. Apply the parking brake while monitoring the brake warning indicator.

Does the brake warning indicator illuminate with the parking brake applied?







3. CHECK THE PARKING BRAKE WARNING INDICATOR SWITCH

1. Ignition OFF.

2. Disconnect: Parking Brake Position Switch.

3. Connect a fused jumper wire:





4. Ignition ON.

Does the brake warning indicator illuminate?







4. CHECK THE PARKING BRAKE WARNING INDICATOR SWITCH GROUND CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Measure:





Is the resistance less than 3 ohms?







5. CHECK THE PARKING BRAKE WARNING INDICATOR SIGNAL CIRCUIT FOR AN OPEN

1. Disconnect: BCM (Body Control Module) C2280C.

2. Measure:





Is the resistance less than 3 ohms?







6. CHECK THE BRAKE FLUID LEVEL SWITCH OPERATION

1. Ignition OFF.

2. Disconnect: Brake Fluid Level Switch.

3. Ignition ON.

4. Wait 1 minute.

Does the brake warning indicator illuminate?







7. CHECK THE BRAKE FLUID LEVEL SIGNAL CIRCUIT FOR A SHORT TO GROUND

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280A.

3. Measure:





Is the resistance greater than 10,000 ohms?







8. CHECK FOR CORRECT BCM (Body Control Module) OPERATION

1. Ignition OFF.

2. Disconnect and inspect all BCM (Body Control Module) connectors.

3. Repair:

- corrosion (install new connector or terminals- clean module pins)
- damaged or bent pins- install new terminals/pins
- pushed-out pins- install new pins as necessary

4. Reconnect the BCM (Body Control Module) connectors. Make sure they seat and latch correctly.

5. Operate the system and determine if the concern is still present.

Is the concern still present?