Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read Body Control Module (BCM) DTCs and record on the repair order.
2. Record the Environmental Data.
3. With the scan tool, erase DTCs.
4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. With the scan tool, read BCM DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR INTERMITTENT CONDITIONS procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE LEFT MULTIFUNCTION SWITCH FOR PROPER OPERATION
1. Turn the ignition off.
2. Disconnect the Left Multifunction Switch harness connector.
3. Measure the resistance at the Left Multifunction Switch (component-side) between terminals 1 and 10.
4. Position the Left Multifunction Switch in the five Turn Signal positions and record the resistance values for each switch position.
5. Compare the recorded resistance values to the Left Multifunction Switch Resistance Values in the Theory of Operation.
  Are the recorded resistance values similar to the Left Multifunction Switch Resistance Values?
  
  Yes
  - Go To 3
  No
  - Replace the Left Multifunction Switch in accordance with the Service Information. Refer to SWITCH, MULTIFUNCTION, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (L305) TURN SIGNALS CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition on.
2. Measure the voltage on the (L305) Turn Signals circuit at the Left Multifunction Switch harness connector.
  Is the voltage greater than 2.5 volts?
  
  Yes
  - Repair the short to voltage on the (L305) Turn Signals circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 4
CHECK THE BCM FOR PROPER OPERATION
1. Turn the ignition off.
2. Connect a jumper wire between ground and the (L305) Turn Signals circuit at the Left Multifunction Switch harness connector.
3. Turn the ignition on.
4. Activate the Turn Lamps in all switch positions.
5. With the scan tool, read BCM DTCs.
  Does the scan tool display DTC: B1051-11-COLUMN SWITCH MODULE TURNLIGHTS-CIRCUIT SHORT TO GROUND as active?
  
  Yes
  - Replace the Left Multifunction Switch in accordance with the Service Information. Refer to SWITCH, MULTIFUNCTION, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 5
CHECK THE (L305) TURN SIGNALS CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the BCM C8/H harness connector.
3. Measure the resistance of the (L305) Turn Signals circuit between the Left Multifunction Switch harness connector - terminal and BCM C8/H harness connector - terminal 18.
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the open or high resistance in the (L305) Turn Signals circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 6
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all BCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. 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.
5. Connect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read BCM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Body Control Module (BCM) in accordance with the Service Information. Refer to MODULE, BODY CONTROL (BCM), 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.