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. Turn the ignition on.
2. With a scan tool, read all DTCs and record on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the Stored Lost Communication DTCs diagnostic procedure. Refer to STORED LOST COMMUNICATION DTCS .
CHECK THE (A18) FUSED B+ CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the VSM 2 harness connector.
3. Measure the voltage on the (A18) Fused B+ circuit at the VSM 2 harness connector.
  Is the voltage equal to Battery voltage?
  
  Yes
  - Go To 3
  No
  - Repair the (A18) Fused B+ circuit for an open.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 3.2L .
CHECK THE (F944) FUSED RUN/START RELAY OUTPUT CIRCUIT FOR A SHORT TO GROUND
1. Check for continuity between ground and the (F944) Run/Start Relay Output circuit at the VSM 2 harness connector.
  Is there continuity between ground and the (F944) Run/Start Relay Output circuit?
  
  Yes
  - Go To 4
  No
  - Repair the (F944) Run/Start Relay Output circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 3.2L .
CHECK THE (F944) FUSED RUN/START RELAY OUTPUT CIRCUIT FOR AN OPEN
1. Turn the ignition on.
2. Measure the voltage on the (F944) Run/Start Relay Output circuit at the VSM 2 harness connector.
  Is the voltage equal to Battery voltage?
  
  Yes
  - Go To 5
  No
  - Repair the (F944) Run/Start Relay Output circuit for an open.
CHECK THE (D403) LIN BUS CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the BCM C4 harness connector.
3. Check for continuity between ground and the (D403) LIN Bus circuit at the VSM 2 harness connector.
  Is there continuity between ground and the (D403) LIN Bus circuit?
  
  Yes
  - Go To 6
  No
  - Repair the (D403) LIN Bus circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 3.2L .
CHECK THE (D403) LIN BUS CIRCUIT FOR AN OPEN
1. Measure the resistance of the (D403) LIN Bus circuit between the VSM 2 harness connector and the BCM C4 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the (D403) LIN Bus circuit for an open.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 3.2L .
CHECK THE VOLTAGE STABILITY MODULE FOR PROPER OPERATION
1. Review all recorded DTCs from step 1.
  Are the PCM or any other modules reporting a Loss of Communication with the BCM
  
  Yes
  - Replace the BCM in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 3.2L .
  No
  - Replace the VSM 2 in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST, 3.2L .