Diagnostic Routine M

Diagnostic Routine M

Diagnostic Overview

All The Stoplamps Are Inoperative

Refer to Wiring Diagram Set 90 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

REFER to Stoplamps .

REFER to Stoplamp Switch .

Visual Inspection and Diagnostic Pre-checks

- Inspect the BJB (Battery Junction Box) fuse 21 (5A) (stoplamp switch).

- Inspect the stoplamp switch for damage.

Pinpoint Test

1. CHECK THE STOPLAMP SWITCH VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect: Stoplamp Switch.

3. Measure:





Is the voltage greater than 11 volts?







2. BYPASS THE STOPLAMP SWITCH

1. Connect a fused jumper wire:





2. Ignition ON.

Do the stoplamps illuminate?







3. CHECK THE STOPLAMP SWITCH INPUT CIRCUIT FOR AN OPEN

1. Ignition OFF.

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

3. Measure:





Is the voltage greater than 11 volts?







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

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

2. 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

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

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

Is the concern still present?