Diagnostic Test

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 Next Step.

   No 

   • Perform the TESTING FOR INTERMITTENT CONDITIONS procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .

1. Check for any applicable Service Bulletins or Flash updates related to the DTC.

   Are there any applicable Service Bulletins or Flash updates?

   Yes 

   • Perform the applicable repair.
   • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

   No 

   • Go To Next Step.

1. Turn the ignition off.
2. Disconnect the related BCM harness connector.
3. With the ignition off, measure the voltage on the Fused Ignition Switch Output circuit at the related BCM harness connector.

   Is there any voltage present?

   Yes 

   • Go To Next Step.

   No 

   • Go To  7.

1. Turn the ignition off.
2. Disconnect the related RFH and BCM harness connectors.
3. Measure the voltage on the Fused Ignition Switch Output circuit at the related BCM harness connector.

   Is any voltage present?

   Yes 

   • Repair the Fused Ignition Switch Output circuit for a short to voltage.
   • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

   No 

   • Go To Next Step.

1. Turn the ignition off.
2. Disconnect the RFH harness connector.
3. Disconnect the BCM harness connector.
4. Measure the resistance of the Fused Ignition Switch Output circuit between the RFH harness connector and the BCM harness connector.

   Is the resistance below 3.0 Ohms?

   Yes 

   • Go To Next Step.

   No 

   • Repair the Fused Ignition Switch Output circuit for an open or high resistance.
   • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

1. Turn the ignition off.
2. Check for continuity between ground and the Fused Ignition Switch Output circuit at the related BCM harness connector.

   Is there continuity between ground and the Fused Ignition Switch Output circuit?

   Yes 

   • Repair the short to ground in the Fused Ignition Switch Output circuit.
   • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

   No 

   • Go To  9.

1. Turn the ignition off.
2. Disconnect the related BCM harness connector.
3. Turn the ignition to the ON position.
4. With the ignition ON, measure the voltage on the Fused Ignition Switch Output circuit at the related BCM harness connector.

   Is there approximately battery voltage present?

   Yes 

   • Go To  10.

   No 

   • Go To Next Step.

Read the CIRCUIT LOAD TESTING PROCEDURE for information on building a simple load test tool, additional load testing information and alternative methods of load testing or voltage drop testing a circuit. Refer to CIRCUIT LOAD TESTING PROCEDURES .

1. Disconnect the RF Hub Module harness connector.
2. Connect one lead of the load test tool to the power supply circuit and the other lead of the load test tool to the ground circuit.
3. Ensure that the power supply circuit is being powered on.
4. If there is no resistance in either circuit the bulb on the load test tool should be illuminated and bright. Compare the brightness of the bulb in the load test tool to that of a direct connection to battery.
   NOTE:

   To verify with certainty that the circuit is good, perform a simple voltage drop test across the 3156 bulb of the load test tool. The voltage drop across the bulb should be equal to the voltage reading across the battery terminals if there is no resistance in either circuit. 

   NOTE:

   A 12-volt test light can be substituted for the load test tool, but only if the test light draws enough current to effectively load test the circuit. Many high impedance test lights draw very little amperage (less than 0.1 amps) and are not reliable to load test a circuit. To perform a proper load test of a circuit, the tool being used should draw more than approximately 0.75 amps. 

   Is the load test bulb illuminated and bright?

   Yes 

   • Go To Next Step.

   No 

   • If the circuits fail the load test, remove the lead connected to the ground circuit and connect it to a good chassis ground. Check the bulb illumination and voltage drop across the 3156 bulb of the load test tool again. If the bulb is not bright or the voltage drop is still less than battery voltage, repair the battery supply circuit for an open or high resistance. If the bulb is bright or the voltage drop is now equal to battery voltage, repair the ground circuit for an open or high resistance.
   • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

1. Disconnect all RF Hub Module 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 RF Hub Module 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 Radio Frequency (RF Hub) Module in accordance with the Service Information. Refer to MODULE, RADIO FREQUENCY (RF HUB), 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.

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.