Diagnostic Test

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

CHECK FOR AN ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool, record all freeze frame data and record any DTCs on the repair order.
3. With the scan tool, erase DTCs in the PCM.
4. Start the engine and allow it to reach normal operating temperature.
5. With the scan tool, select View DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK FOR OTHER DTCS
1. Refer to the recorded DTCs.
  Are there any Sensor Reference voltage, MAF, Intake Air, Turbocharger, or EGR DTCs active or pending?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to DTC INDEX .
  No
  - Go To 3
CHECK THE AIR FILTER FOR PROPER AIR FLOW
1. Turn the ignition off.
2. Remove and inspect the Air Filter for soiling or excessive dirt and debris which may cause air flow restriction
  Were any of these problems found?
  
  Yes
  - Replace the Air Filter in accordance with the service information. Refer to AIR CLEANER, REMOVAL .
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE AIR INTAKE SYSTEM FOR AIR RESTRICTIONS
NOTE:
Inspect all air intake, crankcase vent and turbocharger related tubes for damage, restriction or poor connection. Any of these conditions can cause this DTC to set.

NOTE:
Inspect the exhaust system and related tubes for damage, restriction or poor connection. Any of these conditions can cause this DTC to set.
1. Inspect the intake system, exhaust system and related tubes and connections.
  Were any problems found?
  
  Yes
  - Repair or replace as necessary.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
CHECK THE AIR INTAKE SYSTEM FOR AIR LEAKS
1. Remove the Inlet Pressure Sensor.
2. Connect smoke machine 84-04 to the Inlet Pressure Sensor port in the intake duct and begin injecting smoke into the intake system.
3. Observe all intake system components for evidence of smoke leakage.
  Is there evidence of smoke leakage?
  
  Yes
  - Repair or replace as necessary.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
CHECK THE (F343) FUSED ASD RELAY OUTPUT CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the MAF harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, probe the (F343) Fused ASD Relay Output circuit at the MAF harness connector.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go To 7
  No
  - Repair the (F343) Fused ASD/Main Relay Output circuit for an open or high resistance.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (Z909) GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Using a 12-volt test light connected to B+, probe the (Z909) Ground circuit at the MAF harness connector.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go To 8
  No
  - Repair the (Z909) MAF/Intake Air Sensor Main Ground circuit for an open or high resistance.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE EGR VALVE FOR A STUCK OPEN CONDITION
NOTE:
An EGR Valve that is stuck partially open can cause this DTC to set. Hard starting, rough running and black smoke from the tailpipe are signs of an EGR Valve that is stuck open.
1. While starting and test driving the vehicle, observe for the conditions mentioned in the note above.
  Does the vehicle exhibit these conditions?
  
  Yes
  - Replace the EGR Valve in accordance with the service information. Refer to VALVE, EXHAUST GAS RECIRCULATION (EGR), REMOVAL .
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the Mass Air Flow Sensor in accordance with the service information. Refer to SENSOR, MASS AIRFLOW (MAF), REMOVAL .
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .