Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Test drive the vehicle and operate all of the speed control switch positions.
2. With the scan tool, read DTCs
  Does the scan tool display this DTC as active?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT DTC diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE S/C SIGNAL 1 CIRCUIT
1. Turn the ignition off.
  WARNING:
  Turn the ignition off disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.
2. Remove the Driver Air Bag in accordance with the Service Information. Refer to AIR BAG, DRIVER, REMOVAL .
  WARNING:
  Do not place an intact non-deployed airbag face down on a hard surface, the airbag propels into the air if accidentally deployed. Failure to follow these instructions may result in possible serious or fatal injury.
3. Back probe the S/C Signal 1 circuit at the Right Steering Wheel Switch harness connector.
4. Turn the ignition on.
5. Measure the voltage on the S/C Signal 1 circuit at the Steering Wheel Switch harness connector.
  Is the voltage between 4.9 and 5.1 volts?
  
  Yes
  - Check for spread terminals at the connector. If the connector and terminals are good, replace the Right Steering Wheel Switch in accordance with the Service Information. Refer to SWITCH, SPEED CONTROL, REMOVAL .
    NOTE:
    If the P0579 and P0591 DTCs are both present simultaneously, the most likely cause is resistance in the S/C Switch Ground circuit which is shared by both sensors. If both faults are present, check the sensor ground for high resistance before replacing the switch.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE S/C SIGNAL 1 CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Right Steering Wheel Switch harness connector.
3. Disconnect the PCM C1 harness connector.
4. Measure the resistance of the S/C Signal 1 circuit between the Steering Wheel Switch harness connector and the PCM C1 harness connector.
  Is the resistance below 2.0 Ohms?
  
  Yes
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE STEERING WHEEL HARNESS
1. Disconnect and remove the Steering Wheel Switch harness from the Steering Wheel Switch and SCM.
2. Measure the resistance of the S/C Signal 1 circuit in the Steering Wheel Switch harness.
  Is the resistance below 2.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Replace the Steering Wheel harness.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE CLOCKSPRING/STEERING CONTROL MODULE
1. Disconnect the Steering Control Module C2 harness connector.
2. Measure the resistance of the (V37) S/C Signal 1 circuit between the Steering Control Module C2 and the PCM C1 harness connector.
  Is the resistance below 2.0 Ohms?
  
  Yes
  - Replace the Steering Control Module in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Repair the (V37) S/C Signal 1 circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .