Diagnostic Test

WARNING: This page is about a different car, the 2009 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
  NOTE: Make sure the IOD fuse is installed and battery voltage is between 10.0 and 16.0 volts.
2. With the scan tool, select ECU view.
  NOTE: A red "X" will be next to the module that is not communicating, indicating that the module is not active on the Bus network. A green check indicates that the module is active on the Bus network.
  
  NOTE: Check the FCM for any active CAN C hardware DTCs, perform DTC before proceeding.
  
  Does the scan tool display a red "X" next to the module?
  
  Yes
  - Go to step 2
  No
  - The no response 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.
ATTEMPT TO COMMUNICATE WITH THE PCM
1. With the scan tool in ECU view, observe the status of the PCM.
  Does the scan tool display a red "X" next to the PCM?
  
  Yes
  - Perform the NO RESPONSE FROM PCM diagnostic procedure.
  No
  - Go to step 3
(Z903) GROUND CIRCUIT OPEN

Fig 1: Checking Ground Circuit For Open
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the PCM C4 harness connector.
  CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install PCM Pinout Box 8815 to perform diagnosis.
3. Using a 12-volt test light connected to 12-volts, check each (Z903) ground circuit.
  Does the test light illuminate brightly for each circuit?
  
  Yes
  - Replace and program the Powertrain Control Module in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Repair the (Z903) ground circuit for an open.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .