Diagnostic Test

WARNING: This page is about a different car, the 2020 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read 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 Drivetrain Control Module (DTCM) 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 THE (T315) TRANSFER CASE MOTOR CONTROL A CIRCUIT FOR A SHORT TO GROUND
1. The ignition must be off when checking a circuit for continuity to ground.
2. Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and each component harness connector containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage and corrosion.
3. Connect the negative lead of the Digital Volt-Ohm Meter (DVOM) to a known good ground.
4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.
  NOTE:
  When probing a circuit at an ECU harness connector, always use an appropriate back probing tool to prevent any possible damage to the terminals.
  
  Is there continuity between ground and the circuit being tested?
  
  Yes
  - Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (T316) TRANSFER CASE MOTOR CONTROL B CIRCUIT FOR A SHORT TO GROUND
1. The ignition must be off when checking a circuit for continuity to ground.
2. Isolate the circuit by disconnecting the ECU and each component harness connector containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage and corrosion.
3. Connect the negative lead of the DVOM to a known good ground.
4. With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.
  NOTE:
  When probing a circuit at an ECU harness connector, always use an appropriate back probing tool to prevent any possible damage to the terminals.
  
  Is there continuity between ground and the circuit being tested?
  
  Yes
  - Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (T315) TRANSFER CASE MOTOR CONTROL A CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT AT THE ECU HARNESS CONNECTOR
1. The ignition must be off when performing a resistance check to find a short between circuits.
2. Isolate the circuit by disconnecting the ECU and each component harness connector containing the circuit being tested. Note : Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage and corrosion.
3. Connect one lead of the DVOM to the circuit being tested at the ECU harness connector.
4. With the other lead of the DVOM probe all other circuits at the ECU harness connector.
  NOTE:
  When probing a circuit at an ECU harness connector, always use an appropriate back probing tool to prevent damage to the terminals.
  
  Is there continuity between the circuit being tested and any other circuit?
  
  Yes
  - Repair the circuit for a short to another circuit. Use the wiring diagram as a guide to trace the circuits and look for any in-line connectors to help isolate the location of the short.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
  No
  - Go To 5
CHECK THE (T316) TRANSFER CASE MOTOR CONTROL B CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT AT THE ECU HARNESS CONNECTOR
1. The ignition must be off when performing a resistance check to find a short between circuits.
2. Isolate the circuit by disconnecting the ECU and each component harness connector containing the circuit being tested. Note : Use the wiring diagram as a guide to follow the path of the circuit. Check the disconnected connectors and related harnesses for damage and corrosion.
3. Connect one lead of the DVOM to the circuit being tested at the ECU harness connector.
4. With the other lead of the DVOM probe all other circuits at the ECU harness connector.
  NOTE:
  When probing a circuit at an ECU harness connector, always use an appropriate back probing tool to prevent damage to the terminals.
  
  Is there continuity between the circuit being tested and any other circuit?
  
  Yes
  - Repair the circuit for a short to another circuit. Use the wiring diagram as a guide to trace the circuits and look for any in-line connectors to help isolate the location of the short.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
  No
  - Go To 6
REPLACE THE REAR DRIVELINE MODULE (RDM) HYDRAULIC PUMP MOTOR AND CHECK FOR THE DTC TO RETURN
1. Replace the RDM Hydraulic Pump Motor in accordance with the Service Information. Refer to MOTOR, PUMP, REMOVAL .
2. Connect the RDM Hydraulic Pump Motor and DTCM harness connectors.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Using the recorded Environmental Data and the When Monitored conditions, operate the vehicle in the conditions that set the DTC.
6. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 7
  No
  - The new RDM Hydraulic Pump Motor repaired the problem.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all DTCM 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.
5. Reconnect all DTCM 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 DTCM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the DTCM in accordance with the Service information. Refer to MODULE, DRIVETRAIN CONTROL (DTCM), REMOVAL .
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .