Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
Low battery voltage can cause excessive current draw in very hot and cold ambient temperatures. Make sure the battery can pass a load test before continuing. Review Freeze Frame information to determine the ambient temperature when the DTC set.
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 .
    NOTE:
    If this DTC sets intermittently, it is possible that the controller is overheating in extremely hot temperatures. This is considered a normal protection operation. No repair is necessary.
CHECK THE (K124) ETC MOTOR (+) CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Throttle Body harness connector.
3. Disconnect the PCM C2 harness connector.
4. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
5. Measure the resistance of the (K124) ETC Motor (+) circuit between the Throttle Body harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the (K124) ETC Motor (+) circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K126) ETC MOTOR (-) CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K126) ETC Motor (-) circuit from the Throttle Body harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (K126) ETC Motor (-) circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK FOR THE ETC MOTOR CIRCUITS SHORTED TO 12 VOLTS
1. Reconnect the Throttle Body 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 Throttle Follower Test.
5. Slowly press and release the Accelerator Pedal while monitoring the voltage.
6. Measure the voltage on the (K124) ETC Motor (+) circuit at the GPEC Adaptor.
7. Measure the voltage on the (K126) ETC Motor (-) 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 (K124) ETC Motor (+) circuit or (K126) ETC Motor (-) 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.
    
    Go To 5
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
THROTTLE BODY
1. Connect the voltmeter positive lead to the (K124) ETC Motor (+) circuit.
2. Connect the voltmeter negative lead to the (K126) ETC Motor (-) circuit.
3. With the scan tool, actuate the Throttle Follower Test.
4. Slowly press and release the Accelerator Pedal while monitoring the voltage.
  Is the voltage changing as the Throttle Body Valve position changes?
  
  Yes
  - If a short to voltage has been repaired on either of the ETC Motor circuits in the previous step, repair is complete. If not, replace the Throttle Body Assembly. Refer to THROTTLE BODY, REMOVAL AND INSTALLATION . Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, use a scan tool and select the ETC RELEARN function.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Powertrain Control Module in accordance with the Service information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  - Test complete.