Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, record and erase all DTCs.
3. Start the engine and allow it to idle.
4. With a scan tool, read active DTCs.
  Is the DTC active?
  
  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 Supply, TPS, Oxygen Sensor, Fuel related 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 AIR INLET SYSTEM FOR A RESTRICTION
NOTE:
The most likely cause of this DTC is a plugged intake air system or dirty Throttle Body.
1. Turn the ignition off.
2. Remove the Air Cleaner Assembly.
3. Remove the Air Filter.
4. Inspect the Throttle Body opening for signs of any foreign materials or excessive carbon build up.
5. Check the intake tube and air cleaner for obstructions; include snow packing questions to customer.
  Were any restrictions found?
  
  Yes
  - Repair the restriction as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
COMPARE THE ACTUAL 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.
  Compare the scan tool reading to the vacuum gauge reading?
  
  Both of the readings match
  - Remove the Air Cleaner Assembly and check for restrictions in the filter or assembly. Check for restriction in the air inlet plumbing. Check the Throttle Body for any signs of binding, sticking or obstructions. Repair as necessary in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  MAP reading on scan tool does not match the measured vacuum
  - Go To 5
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 6
  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 7
  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 8
  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 9
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 10
  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 11
No
- Replacing the faulty Throttle Body repaired the fault.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. 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.
5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. 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 .