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 10.0 and 16.0 volts.
1. Turn the ignition on.
2. With the scan tool, read DTCs.
3. Cycle the ignition from off to on.
4. With the scan tool, read DTCs.
  Is the DTC active at this time?
  
  Yes
  - Go To 2
  No
  - Go To 9
CHECK DRIVETRAIN CONTROL MODULE (DTCM)
1. Turn the ignition on.
2. Disconnect the DTCM C1 connector.
3. Using a volt meter, check the voltage of the Private Controller Area Network (CAN) circuits (D442, D443) at terminals 9 and 10
  Was the voltage between 2.2 volts and 2.7 volts?
  
  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
  - Go To
    Refer to 3.
CHECK THE (A197) FUSED B(+) CIRCUIT FOR AN OPEN OR SHORT
1. Turn the ignition off.
2. Disconnect the Power Transfer Unit (PTU) harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, check the (A197) Fused B(+) circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 4
  No
  - Repair the (A197) Fused B(+) circuit for an open or short.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
CHECK THE (F946) FUSED IGNITION RUN/START CONTROL OUTPUT CIRCUIT FOR AN OPEN OR SHORT
1. Using a 12-volt test light connected to ground, check the (F946) Fused Ignition Run/Start Control Output circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 5
  No
  - Repair the (F946) Fused Ignition Run/Start Control Output circuit for an open or short.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
CHECK THE (Z904) GROUND CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Using a 12-volt test light connected to 12-volts, check the (Z904) Ground circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 6
  No
  - Repair the (Z904) Ground circuit for an open.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
CHECK THE (D443) PRIVATE CAN (+) CIRCUIT FOR AN OPEN
1. Disconnect the DTCM C1 harness connector.
2. Measure the resistance of the (D443) Private CAN (+) circuit between the PTU harness connector and the DTCM C1 harness connector.
  Is the resistances below 3.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the (D443) Private CAN (+) circuit for an open.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
CHECK THE (D442) PRIVATE CAN (-) CIRCUIT FOR AN OPEN
1. Measure the resistance of the (D442) Private CAN (-) circuit between the PTU harness connector and the DTCM C1 harness connector.
  Are the resistances below 3.0 Ohms?
  
  Yes
  - Go To 8
  No
  - Repair the (D442) Private CAN (-) circuit for an open.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
PTU
1. Turn the ignition on.
2. With the scan tool, read DTCs.
3. Cycle the ignition from off to on.
4. With the scan tool, read DTCs.
  Does the DTC remain active?
  
  Yes
  - Replace the PTU in accordance with the Service Information.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
  No
  - Go To 9
INTERMITTENT WIRING HARNESS AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the wiring diagram/schematic as a guide, inspect the wiring harness and connectors for any sign of worn or bent pins, broken or frayed wires or corroded connectors or pins.
3. Check the routing of the wire harness making sure that the harness does not interfere with the shift cable.
4. Wiggle test the wiring harness and connectors while monitoring the scan tool data relative to this circuit.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. While monitoring the scan tool data related to this circuit, move the selector switch to each position several times.
7. Look for the data to change other than as expected or for the DTC to reset.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the DTCM VERIFICATION TEST. Refer to DTCM VERIFICATION TEST .
  No
  - Test complete.