Diagnostic Test

WARNING: This page is about a different variant/trim than selected.

CHECK FOR AN ACTIVE DTC
NOTE:
Low battery voltage can also cause excessive current draw, in very hot and very cold ambient temperatures. Make sure the battery can pass a load test before continuing.
1. Turn the ignition on.
2. With the scan tool, read DTCs and record on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K873) SCB VALVE CONTROL (+) CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Supercharger Bypass Valve harness connector.
3. Disconnect the PCM C2 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 the GPEC Diagnostic Adaptor to perform the diagnosis.
4. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
5. Measure the resistance of the (K873) SCB Valve Control (+) circuit from the Supercharger Bypass Valve harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the (K873) SCB Valve Control (+) circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K874) SCB VALVE CONTROL (-) CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K874) SCB Valve Control (-) circuit from the Supercharger Bypass Valve harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K874) SCB Valve Control (-) circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK FOR THE SCB VALVE CONTROL CIRCUITS SHORTED TO 12 VOLTS
1. Reconnect the SCB Valve harness connector.
2. Reconnect the PCM C2 harness connector with the GPEC Adaptor still connected in line.
3. Turn the ignition on.
4. With the scan tool, actuate the Supercharger Bypass Valve.
5. Measure the voltage on the (K873) SCB Valve Control (+) circuit at the GPEC Adaptor.
6. Measure the voltage on the (K874) SCB Valve Control (-) circuit at the GPEC Adaptor.
  NOTE:
  The voltage reading should change as the valve position is changed. A reading that stays at 12 volts would indicate a short to voltage.
  
  Is the voltage reading steady at 12 volts for either circuit?
  
  Yes
  - Repair the (K873) SCB Valve Control (+) circuit or (K874) SCB Valve Control (-) circuit for a short to voltage.
    NOTE:
    A short to voltage on the motor circuits can damage the internal H-Bridge driver of the PCM and cause it to be open. After repairing the short to voltage, verify that the PCM was not damaged.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
SUPERCHARGER BYPASS VALVE OPERATION
1. Connect the voltmeter positive lead to the (K873) SCB Valve Control (+) circuit.
2. Connect the voltmeter negative lead to the (K874) SCB Valve Control (-) circuit.
3. With the scan tool, actuate the Supercharger Bypass Valve.
  Is the voltage changing as the SCB Valve position changes?
  
  Yes
  - If a short to voltage as repaired on either of the SCB Valve Control circuits in the previous step, repair is complete. If not, replace the Supercharger Bypass Valve Assembly in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
SUPERCHARGER BYPASS VALVE INSPECTION
1. Turn the ignition off.
2. Remove the Throttle Body and use a bore scope camera or small mirror to view the Supercharger Bypass Valve.
3. Inspect for any signs of coking or a foreign material (ice or dirt) on the Supercharger Bypass Valve plate or in the bore causing the Supercharger Bypass Valve plate to stick prevent operation. Inspect for damage or scoring to Supercharger. Turn the ignition on and use the scan tool to actuate the Supercharger Bypass Valve and check for any sticking.
  Were any signs of foreign material or scoring of the Supercharger or Supercharger Bypass Valve plate or bore found?
  
  Yes
  - Inspect Supercharger for debris or internal damage. Repair as necessary. Clean the throttle blade and bore if possible or replace the Supercharger Bypass Valve in accordance with the Service Information if necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7
SUPERCHARGER BYPASS VALVE
1. Replace the Supercharger Bypass Valve Assembly in accordance with the Service Information.
2. Turn the ignition on.
3. With the scan tool, erase DTCs.
4. Start the engine and test drive the vehicle.
5. With the scan tool, read DTCs and record on the repair order.
  Did the DTC return?
  
  Yes
  - Go To 8
  No
  - Repair is complete.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Supercharger Bypass Valve and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Supercharger Bypass Valve and Powertrain Control Module connectors.
4. Perform any Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .