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Home >> Jeep >> 2009 >> Commander Overland, RWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> Can Communication System - Non-DTC Diagnostics >> Diagnosis and Testing >> No Response From SCM (Steering Control Module) >> Diagnostic Test
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Diagnostic Test

  1. TEST FOR INTERMITTENT CONDITION 
    1. Turn the ignition on.
      NOTE: Ensure 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.

      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.
  2. (A108) FUSED B(+) CIRCUIT OPEN OR SHORTED 
    Fig 1: Checking Fused B(+) Circuit For Open Or Short
    GC0132787Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the Steering Control Module C1 harness connector.
    3. Using a 12-volt test light connected to ground, check the (A108) Fused B(+) circuit.

      Does the test light illuminate brightly?

      Yes 

      • Go to step  3

      No 

  3. (Z907) GROUND CIRCUIT OPEN 
    Fig 2: Checking Ground Circuit For Open
    GC0132788Courtesy of CHRYSLER LLC
    1. Using a 12-volt test light connected to 12-volts, check the (Z907) ground circuit.

      Does the test light illuminate brightly?

      Yes 

      • Go to step  4

      No 

  4. (D55) AND (D54) CAN B BUS CIRCUITS OPEN 
    Fig 3: Checking Can B Bus Circuits For Open
    GC0132789Courtesy of CHRYSLER LLC
    NOTE: One open circuit will not cause this condition.
    1. Measure the voltage between the (D54) CAN B Bus (-) circuit and ground.
    2. Measure the voltage between the (D55) CAN B Bus (+) circuit and ground.

      Is there any voltage present on either circuit?

      Yes 

      No