Initial Inspection and Diagnostic Overview

Inspection and Verification
1. Verify the customer concern.
2. Visually inspect for obvious signs of electrical damage.

Visual Inspection Chart:

3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

NOTE: Make sure to use the latest scan tool software release.

4. If the cause is not visually evident, connect the scan tool to the data link connector (DLC).

NOTE: The vehicle communication module (VCM) prove-out confirms power and ground from the DLC are provided to the VCM.

5. If the scan tool does not communicate with the VCM:
- Check the VCM connection to the vehicle.
- Check the scan tool connection to the VCM.
- See PINPOINT TEST 14: NO POWER TO THE SCAN TOOL, to diagnose no communication with the scan tool. Pinpoint Test 14: No Power to the Scan Tool

6. If the scan tool does not communicate with the vehicle:
- Verify the ignition key is in the ON position.
- Verify the scan tool operation with a known good vehicle.
- See PINPOINT TEST 1: THE PCM DOES NOT RESPOND TO THE SCAN TOOL OR NO HIGH SPEED CONTROLLER AREA NETWORK (HS-CAN) COMMUNICATION to diagnose no response from the PCM. Pinpoint Test 1: The PCM Does Not Respond to the Scan Tool or No High Speed Controller Area Network (Hs-CAN) Communication

7. Carry out the network test:
- If the scan tool responds with no communication for one or more modules, see SYMPTOM TROUBLESHOOTING CHART. Symptom Related Diagnostic Procedures
- If the network test passes, retrieve and record the continuous memory DTCs.

8. Clear the continuous DTCs and carry out the self-test diagnostics for the SJB.
9. If the DTCs retrieved are related to the concern, see DTC CHARTS - SMART JUNCTION BOX (SJB). For all other DTCs, see DIAGNOSTIC TROUBLE CODE (DTC) CHART - B, C AND U CODES. Engine Control System
10. If no DTCs related to the concern are retrieved, verify the symptom and see SYMPTOM TROUBLESHOOTING CHART - SMART JUNCTION BOX (SJB).