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.

TEST FOR INTERMITTENT CONDITION
NOTE:
Check for any Service Bulletins related to the condition. If a Service Bulletin applies, perform the procedure outlined in the Service Bulletin before continuing.
1. Turn the ignition on.
  NOTE:
  Make sure the battery voltage is between 10.0 and 16.0 volts.
2. With the scan tool, read the module status.
  NOTE:
  Check the BCM for any active CAN hardware DTCs, perform the diagnostic procedure for those DTCs before proceeding.
  
  Does the scan tool indicate that the module is active on the bus?
  
  Yes
  - The no response condition is not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
  No
  - Go To 2
CHECK THE (A951) FUSED B(+) CIRCUIT FOR AN OPEN OR SHORT
1. Turn the ignition off.
2. Disconnect the Electric Power Steering (EPS) Module C1 and C2 harness connectors.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, check the (A951) Fused B(+) circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 3
  No
  - Repair the (A951) Fused B(+) circuit for an open or short.
  - Perform the EPS VERIFICATION TEST. Refer to EPS VERIFICATION TEST .
CHECK THE (F942) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT FOR AN OPEN OR SHORT
1. Using a 12-volt test light connected to ground, check the (F942) Fused Ignition Switch Output (Run-Start) circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 4
  No
  - Repair the (F942) Fused Ignition Switch Output (Run-Start) circuit for an open or short.
  - Perform the EPS VERIFICATION TEST. Refer to EPS VERIFICATION TEST .
CHECK THE (Z907) GROUND CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Using a 12-volt test light connected to 12-volts, check the (Z907) Ground circuit.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 5
  No
  - Repair the (Z907) Ground circuit for an open.
  - Perform the EPS VERIFICATION TEST. Refer to EPS VERIFICATION TEST .
CHECK THE (D139) CAN C(+) BUS CIRCUIT FOR AN OPEN
1. Disconnect the Star Can C Body C5 harness connector. and perform the CAN C DASH STAR CONNECTOR REMOVAL process. Refer to CONNECTOR, STAR DIAGNOSTIC .
2. Measure the resistance of the (D139) CAN C Bus (+) circuit between the Star Can C Body C5 harness connector and the EPS C1 harness connector.
  Is the resistances below 5.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (D139) CAN C(+) Bus circuit for an open.
  - Perform the EPS VERIFICATION TEST. Refer to CONNECTOR, STAR DIAGNOSTIC .
CHECK THE (D138) CAN C(-) BUS CIRCUIT FOR AN OPEN
1. Measure the resistance of the (D138) CAN C Bus (-) circuit between the Star Can C Body C5 harness connector and the EPS C1 harness connector.
  Are the resistances below 5.0 Ohms?
  
  Yes
  - Replace the Electric Power Steering (EPS) Module in accordance with the Service Information. Refer to GEAR, REMOVAL .
  - Perform the EPS VERIFICATION TEST. Refer to CONNECTOR, STAR DIAGNOSTIC .
  No
  - Repair the (D138) CAN C(-) Bus circuit for an open.
  - Perform the EPS VERIFICATION TEST. Refer to CONNECTOR, STAR DIAGNOSTIC .