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 and any DTCs.
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 AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK FOR VOLTAGE ON THE (G115) DRIVE MODE SELECT SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the Drive Mode Select Switch harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (G115) Drive Mode Select Signal circuit at the Drive Mode Select Switch harness connector.
  Is there any voltage present?
  
  Yes
  - Go To 6
  No
  - Go To 3
CHECK THE (Z912) GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (Z912) Ground circuit between the Drive Mode Select Switch harness connector and the BCM C8/H harness connector.
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the open or high resistance in the (Z912) Ground 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 fused jumper wire between the (Z912) Ground circuit and the (G115) Drive Mode Select Signal circuit at the Drive Mode Select Switch harness connector.
3. Turn the ignition on.
4. With the scan tool, read BCM DTCs.
  Does the scan tool display DTC: B1055-11-DNA DRIVER STILE SWITCH-CIRCUIT SHORT TO GROUND as active?
  
  Yes
  - Replace the Drive Mode Select Switch in accordance with the Service Information. Refer to SHIFTER, TRANSMISSION, REMOVAL AND INSTALLATION, 8HP50/850RE SHIFTER, TRANSMISSION, REMOVAL AND INSTALLATION, 8HP75 ..
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 5
CHECK THE (G115) DRIVE MODE SELECT SIGNAL 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 (G115) Drive Mode Select Signal circuit between the Drive Mode Select Switch harness connector and BCM C8/H harness connector - terminal 21.
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the open or high resistance in the (G115) Drive Mode Select Signal circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 7
CHECK THE (G115) DRIVE MODE SELECT SIGNAL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT IN THE HARNESS CONNECTOR
1. Turn the ignition off.
2. Disconnect the BCM C8/H harness connector.
3. Check for continuity between the (G115) Drive Mode Select Signal circuit and all other circuits on the Drive Mode Select Switch harness connector.
4. Check for continuity between the (G115) Drive Mode Select Signal circuit and all other circuits on the BCM C8/H harness connector.
  Is there continuity between the (G115) Drive Mode Select Signal circuit and any other circuit(s)?
  
  Yes
  - Repair the short between the (G115) Drive Mode Select Signal circuit and the circuit that has continuity.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Inspect the (G115) Drive Mode Select Signal circuit, between the Drive Mode Select Switch and the BCM C8/H harness connector, for a short to voltage. If no problems are found, Go To 7
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. Reconnect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect 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.