Diagnostic Test

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
NOTE:
Make sure the battery voltage is between 10 and 16 volts before proceeding.
1. With the scan tool, read TCM DTCs and record on the repair order.
  Is this DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the STORED LOST COMMUNICATION DTCS diagnostic procedure. Refer to STORED LOST COMMUNICATION DTCS .
CHECK FOR THE FOLLOWING ACTIVE DTCS
1. With the scan tool, read active DTCs from all modules.
  NOTE:
  Check for BCM configuration, CAN C hardware electrical, VIN Missing/Mismatch, battery or ignition related DTCs.
  
  Does the scan tool display any active DTCs to the conditions listed above?
  
  Yes
  - Perform the appropriate diagnostic procedure.
  No
  - Go To 3
VERIFY THE ELECTRIC PARK BRAKE MODULE IS ACTIVE ON THE BUS
1. Turn the ignition on.
2. With the scan tool, verify the Electric Park Brake Module is active on the bus.
  Is the Park Brake Control Module active on the bus?
  
  Yes
  - Go To 4
  No
  - Perform the NO RESPONSE FROM ELECTRIC PARK BRAKE MODULE diagnostic procedure. Refer to NO RESPONSE FROM EPB (ELECTRIC PARKING BRAKE MODULE) .
CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCS
1. With the scan tool, read all DTCs.
  Is there more than one module with active DTCs set against the Electric Park Brake Module?
  
  Yes
  - Replace the Electric Park Brake Module in accordance with the Service Information. Refer to MODULE, ELECTRIC PARK BRAKE (EPBM), REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 5
CLEAR DTC IN MODULE SETTING FAULT
1. With the scan tool, select the module setting the DTC against the Electric Park Brake Module.
2. With the scan tool, erase DTCs.
  Did the DTC return?
  
  Yes
  - Replace the module that set this DTC in accordance with the Service Information.
  - Perform the appropriate verification test for the module being replaced. If there is no verification test for the associated module perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 6
CYCLE IGNITION
1. Cycle the ignition from RUN to OFF three times ending with the key in the RUN position.
  Does this DTC become active?
  
  Yes
  - Go To 7
  No
  - The condition is not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals.
  - Perform the appropriate verification test for the module. If there is no verification test for the associated module Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK FOR ADDITIONAL LOST COMMUNICATION FAULTS
1. With the scan tool, view the modules.
  Does the BCM and other CAN C bus modules show Lost Communication with the remaining CAN C BUS modules?
  
  Yes
  - Go To 8
  No
  - Replace the module that set this DTC in accordance with the Service Information.
  - Perform the appropriate verification test for the module being replaced. If there is no verification test for the associated module perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE CAN C BUS (+) CIRCUIT FOR A SHORT TO VOLTAGE

Courtesy of CHRYSLER GROUP, LLC
1. Measure the voltage between ground and the (D57) CAN C Bus (+) circuit at the Data Link connector.
  Is the voltage above 5.0 volts?
  
  Yes
  - Repair the CAN C Bus (+) circuit for a short to voltage. The short to voltage is present in one of the CAN C Bus circuits. Use the Star Connectors to isolate portions of the CAN C Bus in order to locate the concern.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 9
CHECK THE CAN C BUS (-) CIRCUIT FOR A SHORT TO GROUND

Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Check for continuity between ground and the (D58) CAN C Bus (-) circuit at the Data Link connector.
  Is there continuity between ground and the (D58) CAN C Bus (-) circuit?
  
  Yes
  - Repair the CAN C Bus (-) circuit for a short to ground. The short to ground is present in one of the CAN C Bus circuits. Use the Star Connectors to isolate portions of the CAN C Bus in order to locate the concern.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Replace the module that set this DTC in accordance with the Service Information.
  - Perform the appropriate verification test for the module being replaced. If there is no verification test for the associated module perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .