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) then sends out an ignition status message on the MS-CAN (Medium Speed Controller Area Network) 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 START.

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.

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






2. CHECK FOR START VOLTAGE AT THE PCM (Powertrain Control Module)

1. Ignition OFF.

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

3. Ignition START.

4. 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 PCM (Powertrain Control Module) OPERATION

1. Disconnect and inspect all PCM (Powertrain 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 PCM (Powertrain 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?