Diagnostic Routine I

Diagnostic Routine I

Diagnostic Overview

The Start-Stop Switch Mode Indicator is Always or Never Illuminated

Refer to Wiring Diagram Set 13 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

The BCM (Body Control Module) uses a FET (Field-Effect Transistor) as circuit protection for the start/stop switch indicator and as an electronic switch to turn the start/stop switch indicator on and off. The FET (Field-Effect Transistor) receives fused battery voltage from BCM (Body Control Module) fuse 18 (10A). When the start/stop switch is pressed a voltage and ground signal are sent to the BCM (Body Control Module). When the vehicle enters RUN or START mode, the BCM (Body Control Module) forward biases the FET (Field-Effect Transistor) which provides voltage to the amber LED (Light-emitting Diode) in the start/stop switch, illuminating the word ENGINE.

DTC Fault Trigger Conditions






Pinpoint Test

1. CHECK FOR BCM (Body Control Module) DTCs (Diagnostic Trouble Codes)

1. Using a scan tool, perform BCM (Body Control Module) self-test.

2. Record all BCM (Body Control Module) DTCs (Diagnostic Trouble Codes).

Is DTC (Diagnostic Trouble Code) B1240:11 present?








2. CHECK THE MODE INDICATOR CIRCUIT FOR A SHORT TO GROUND

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280B.

3. Disconnect: Start/Stop Switch.

4. Measure:





Is the resistance to ground greater than 10,000 ohms?








3. CHECK THE MODE INDICATOR CIRCUIT FOR A SHORT TO VOLTAGE

1. NOTE: Disconnecting BCM (Body Control Module) C2280B with the ignition in RUN mode causes DTCs (Diagnostic Trouble Codes) to set in some modules.
Ignition ON.

2. Disconnect: BCM (Body Control Module) C2280B.

3. Disconnect: Start/Stop Switch.

4. Measure:





Is any voltage present?








4. CHECK THE MODE INDICATOR CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280B.

3. Measure:





Is the resistance less than 3 ohms?








5. CHECK START/STOP SWITCH INDICATOR

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280B.

3. Connect a fused jumper wire:





Does the start/stop switch mode indicator illuminate?








6. 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 and all previously disconnected exterior system 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?