Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Start the Engine.
2. With the scan tool, read Instrument Panel Cluster (IPC) DTCs and record on the repair order.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK FOR BODY CONTROL MODULE (BCM) DTCS
1. With the scan tool, read Body Control Module (BCM) DTCs and record on the repair order.
  Are there any dimmer DTCs set in the BCM?
  
  Yes
  - Repair the BCM DTC(s). Refer to DTC TROUBLESHOOTING .
  No
  - Go To 3
CHECK IF OTHER LIGHTS ARE DIMMING
1. While Monitoring other lights on the dimmer circuit, adjust the dimmer switch from high to low and back.
  NOTE:
  Depending on the vehicle options, this can include the cup holder, fuel door switch, media port and center console lamps.
  
  Are other lights working properly with the dimmer being adjusted?
  
  Yes
  - Go To 4
  No
  - Go To 5
CHECK THE (E12) PANEL LAMPS DRIVER CIRCUIT FOR AN OPEN TO THE IPC
1. Turn the ignition off.
2. Disconnect the Headlamp Switch harness connector.
3. Disconnect the IPC harness connector.
4. Check the resistance of the (E12) Panel Lamps Driver circuit between the Headlamp Switch harness connector and the IPC harness connector.
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the (E12) Panel Lamps Driver circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 6
CHECK THE (E12) PANEL LAMPS DRIVER CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the Headlamp Switch harness connector.
3. Disconnect the IPC harness connector.
4. Check the resistance of the (E12) Panel Lamps Driver circuit between the Headlamp Switch harness connector and the IPC harness connector.
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the (E12) Panel Lamps Driver circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Replace the Headlamp Dimmer Switch in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Turn the ignition off.
2. Disconnect all IPC harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
6. Reconnect all IPC harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
11. With the scan tool, read IPC DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Instrument Panel Cluster (IPC) in accordance with the Service Information. Refer to REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  - Test complete.