Inspection and Verification
- Verify the customer concern.
- Visually inspect the following for obvious signs of electrical damage.VISUAL INSPECTION CHART
Electrical - Smart junction box (SJB) fuse 23 (15A)
- Bulb(s)
- Circuitry
- Connectors
- Traction control switch
- Manual climate control switch
- Memory seat switch (if equipped)
- Auxiliary climate control switches (if equipped)
- Door lock control switches
- Window control switches
- Headlamp switch
- Electronic automatic temperature control (EATC) module
- Audio unit
- SJB
- Instrument cluster
- If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- If the cause is not visually evident, connect the scan tool to the data link connector (DLC).
- 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.
- Refer to MODULE COMMUNICATIONS NETWORK , No Power To The Scan Tool, to diagnose no communication with the scan tool.
- 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.
- Refer to MODULE COMMUNICATIONS NETWORK to diagnose no response from the powertrain control module (PCM).
- Carry out the network test.
- If the scan tool responds with no communication for one or more modules, refer to MODULE COMMUNICATIONS NETWORK .
- If the network test passes, retrieve and record the continuous memory DTCs.
- Clear the continuous DTCs and carry out the self-test diagnostics for the SJB.
- If the DTCs retrieved are related to the concern, go to the Smart Junction Box (SJB) Diagnostic Trouble Code (DTC) Chart. For all other DTCs, refer to MULTIFUNCTION ELECTRONIC MODULES .
- If no DTCs related to the concern are retrieved, go to Symptom Chart .
NOTE:
Make sure to use the latest scan tool release software.
NOTE:
The vehicle communication module (VCM) LED prove-out confirms power and ground from the DLC are provided to the VCM.
SMART JUNCTION BOX (SJB) DIAGNOSTIC TROUBLE CODE (DTC) CHART
| DTC | Description | Action |
|---|---|---|
| B2026 | Incandescent Backlighting Output Circuit Failure | Go to Pinpoint Test E . |
| B2027 | LED Backlighting Output Circuit Failure | Go to Pinpoint Test E . |
| B2121 | Illumination Switch Short To Battery | Go to Pinpoint Test E . |
| B2132 | Dimmer Switch Circuit Short to Ground | Go to Pinpoint Test F . |
| All other DTCs | - | REFER to MULTIFUNCTION ELECTRONIC MODULES . |