Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, read active DTCs.
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the appropriate SYSTEM WIRING DIAGRAMS as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K683) EGR SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the EGR Valve harness connector.
3. Disconnect the PCM C2 harness connector.
4. Check for continuity between ground and the (K683) EGR Signal circuit at the EGR Valve harness connector.
  Is there continuity between ground and the (K683) EGR Signal circuit?
  
  Yes
  - Repair the (K683) EGR Signal circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK FOR THE (K683) EGR SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
1. Check for continuity between the (K683) EGR Signal circuit and the (K900) Sensor Ground circuit at the EGR Valve harness connector.
  Is there continuity between the (K683) EGR Signal circuit and the (K900) Sensor Ground circuit?
  
  Yes
  - Repair the (K683) Heated Thermostat Control circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
EGR VALVE
1. Reconnect the PCM C2 harness connector.
2. Connect a jumper between the (F856) 5-Volt Supply circuit and the (K683) EGR Signal circuit at the EGR Valve harness connector.
3. Turn the ignition on.
4. With the scan tool, read active DTCs.
  NOTE:
  The P0406-EGR POSITION SENSOR CIRCUIT HIGH DTC should be active or pending with the jumper in place.
  
  Does the DTC display as described above?
  
  Yes
  - Replace the EGR Valve in accordance with the Service Information. The EGR VALVE REPLACED routine must be performed after replacing or cleaning the EGR Valve to reset the zero learn position. Failure to do so will cause a false failure and the P1404 DTC to set. With the scan tool, perform the EGR VALVE REPLACED routine.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 5
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.