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
1. With the scan tool, read Adaptive Cruise Control (ACC) DTCs Module DTCs and record on the repair order.
2. With the scan tool, erase ACC Module DTCs.
3. Turn the ignition off.
4. Turn the ignition on.
5. With the scan tool, read ACC Module DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Go To 9
CHECK THE (F925) FUSED IGNITION (RUN) CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the Forward Facing Camera Module (FFCM) harness connector.
3. Start the Engine.
4. With a 12-volt test light connected to ground, check the (F925) Fused Ignition (Run) circuit in the FFCM harness connector.
  NOTE:
  The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly?
  
  Yes
  - Go To 3
  No
  - Repair the (F925) Fused Ignition (Run) circuit for an open or high resistance.
    NOTE:
    If the fuse is open, make sure to check for a short to ground.
  - Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (Z912) GROUND CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. With a 12-volt test light connected to 12 volts, check the (Z912) Ground circuit in the FFCM harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 4
  No
  - Repair the (Z912) Ground circuit for an open or high resistance.
  - Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (D449) CAN C(+) AND (D448) CAN C(-) CIRCUITS FOR A SHORT TO GROUND
1. Disconnect the Adaptive Cruise Control (ACC) Module harness connector.
2. Measure the resistance between ground and both (D449) CAN C (+) and (D448) CAN C(-) circuits.
  Is the resistance above 100K Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (D449) CAN C (+) and/or the (D448) CAN C(-) circuit(s) for a short to ground.
  - Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (D449) CAN C(+) AND D448 CAN C(-) CIRCUITS FOR AN OPEN
1. Measure the resistance of both (D449) CAN C (+) and (D448) CAN C(-) circuits between the ACC harness connector and the FFCM harness connector.
  Is the resistance above 2.0 Ohms on either circuit?
  
  Yes
  - Repair the (D449) CAN C (+) and/or the (D448) CAN C(-) circuit(s) for an open or high resistance.
  - Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 6
CHECK THE (D449) CAN C(+) CIRCUIT FOR A SHORT TO THE D448 CAN C(-) CIRCUIT
1. Measure the continuity between the (D449) CAN C (+) and (D448) CAN C(-) circuit at the ACC harness connector.
  Is there continuity between the (D449) CAN C (+) and (D448) CAN C(-) circuit?
  
  Yes
  - Repair the (D449) CAN C (+) circuit for a short to the (D448) CAN C(-) circuit.
  - Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 7
CHECK THE (D449) CAN C(+) AND D448 CAN C(-) CIRCUITS FOR A SHORT TO VOLTAGE
1. Turn the ignition on.
2. Measure the voltage of both the (D449) CAN C (+) and (D448) CAN C(-) circuits between the ACC harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (D449) CAN C (+) and/or the (D448) CAN C(-) circuit(s) for a short to voltage.
  - Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 8
FORWARD FACING CAMERA
1. Replace and program/align the Forward Facing Camera Module (FFCM) in accordance with the Service Information. Refer to MODULE, FORWARD FACING CAMERA (FFCM), REMOVAL .
2. Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  Did the DTC return?
  
  Yes
  - If this DTC resets after replacement of the Forward Facing Camera and no other problems are found, replace and program the Adaptive Cruise Control (ACC) Module in accordance with the Service Information. Refer to MODULE, ADAPTIVE CRUISE CONTROL (ACCM), REMOVAL .
  No
  - Test Complete.
CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this Module. Wiggle the wiring and connectors while checking for shorted and open circuits.
3. Check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
4. Check Service Bulletins for any possible causes that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Test complete.