Diagnostic Test

READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, run and save a vehicle Scan Report and all related recorded data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK FOR OTHER DTCS
1. Refer to the recorded DTCs.
  Are there any 5-Volt Reference, TPS, Cam Sensor, Crank Sensor or MAP Sensor DTCs active or pending?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to DIAGNOSTIC CODE INDEX .
  No
  - Go To 3
CHECK THE PCV VALVE AND SYSTEM FOR LEAKS OR RESTRICTIONS
1. Visually inspect the PCV System for signs of leaks.
2. Check the PCV Valve and system for restricted air flow.
  Were any issues found with the PCV System?
  
  Yes
  - Perform the appropriate repair.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
COMPARE THE ENGINE VACUUM AND MAP SENSOR READING
1. Turn the engine off.
2. Connect a vacuum gauge to the Intake Manifold.
3. Start the engine and allow it to idle.
4. Monitor the reading on the vacuum gauge.
5. Monitor the MAP Sensor reading on the scan tool.
  Does the scan tool reading match the vacuum gauge reading?
  
  Yes
  - Check and repair any engine vacuum leaks, exhaust restrictions, or engine mechanical conditions that can cause low engine compression.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK THE MAP SENSOR AND THROTTLE BODY HARNESS CONNECTORS AND TERMINALS
1. Turn the ignition off.
2. Check the Map Sensor and Throttle Body harness connector for proper connection at the Map Sensor And Throttle Body.
3. Verify that the connector is completely plugged in and locked prior to disconnecting.
4. Disconnect the Map Sensor and Throttle Body harness connectors and check for pushed out or spread terminals, brinelling on terminals, discoloration from excessive heat, or corrosion and water intrusion.
  Were any issues found with the connectors or terminals?
  
  Yes
  - Repair the found issues in accordance with the Service Information or properly connect and lock the Map Sensor or Throttle Body harness connector(s).
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
CHECK FOR HIGH RESISTANCE IN THE (F856) 5-VOLT SUPPLY CIRCUIT
1. Turn the ignition off.
2. Disconnect the MAP Sensor 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 (F856) 5-Volt Supply circuit between the MAP Sensor harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the (F856) 5-Volt Supply circuit for high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK FOR HIGH RESISTANCE IN THE (K1) MAP SIGNAL CIRCUIT
1. Measure the resistance of the (K1) MAP Signal circuit between the MAP Sensor harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 8
  No
  - Repair the (K1) MAP Signal circuit for high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK FOR HIGH RESISTANCE IN THE (K900) SENSOR GROUND CIRCUIT
1. Measure the resistance of the (K900) Sensor Ground circuit between the MAP Sensor harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 9
  No
  - Repair the (K900) Sensor Ground circuit for high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE MAP SENSOR AND PORT FOR OBSTRUCTIONS
1. Remove the MAP Sensor.
2. Inspect the MAP Sensor and port for any obstructions.
  Were any obstructions found?
  
  Yes
  - Perform the appropriate repairs and retest.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 10
REPLACE THE MAP SENSOR AND RETEST FOR DTC
1. Replace the MAP Sensor in accordance with the Service Information. Refer to SENSOR, MANIFOLD ABSOLUTE PRESSURE (MAP), REMOVAL AND INSTALLATION .
2. Turn the ignition on.
3. With the scan tool, erase DTCs.
4. Start the engine and allow it to idle until closed loop fueling is achieved.
5. With a scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 11
  No
  - Replacing the MAP Sensor repaired the fault.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
REPLACE THE THROTTLE BODY AND RETEST FOR DTCS
1. Replace the Throttle Body in accordance with the Service Information. Refer to THROTTLE BODY, REMOVAL AND INSTALLATION .
2. Connect the Throttle Body and PCM harness connectors.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Using the Environmental Data or When Monitored Conditions above, operate the vehicle within the conditions that set the DTC.
6. With the scan tool, read DTCs.
Did the DTC return?

Yes
- Go To 12
No
- Replacing the faulty Throttle Body repaired the fault.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
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 and program the Powertrain Control Module (PCM) 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
  - The wiring or poor connection problem has been repaired.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .