Diagnostic Routine D

Diagnostic Routine D

Diagnostic Overview

No Power in START - Vehicles with an Ignition Switch

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

Refer to Wiring Diagram Set 20 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

When the ignition switch is turned to the START position, a voltage signal is sent to the BCM (Body Control Module) and the PCM (Powertrain Control Module). The BCM (Body Control Module) sends out a voltage signal to various modules to indicate a start event and the PCM (Powertrain Control Module) checks various inputs and bus messages in an effort to start the vehicle.

Pinpoint Test

1. CHECK THE KEY POSITION FOR START INDICATED (START_KEY) PID (Parameter Identification)

1. Ignition ON.

2. Using a scan tool, view the PCM (Powertrain Control Module) PIDs (Parameter Identifications).

3. Monitor the PCM (Powertrain Control Module) PID (Parameter Identification) START_KEY.

4. Momentarily turn the key to START and release it.

Does the PID (Parameter Identification) read On when the ignition is in the START position?








2. CHECK FOR VOLTAGE TO THE BCM (Body Control Module) AND PCM (Powertrain Control Module)

1. Ignition OFF.

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

3. Disconnect: PCM (Powertrain Control Module) C175B.

4. With the ignition switch in the START position, measure:





Is the voltage greater than 11 volts?








3. CHECK THE IGNITION START CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect: Ignition Switch.

3. Measure:





Is the resistance less than 3 ohms?








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 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?