Diagnostic Test
- CHECK FOR AN ACTIVE DTC
- Turn the ignition on.
- 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 (F856) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
- Turn the ignition off.
- Disconnect the EGR Valve harness connector.
- Turn the ignition on.
- Measure the voltage on the (F856) 5-Volt Supply circuit at the EGR Valve harness connector.
Is the voltage above 5.2 volts?
Yes
- Repair the (F856) 5-Volt Supply circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 3
- CHECK THE (K683) EGR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
- Measure the voltage on the (K683) EGR Signal circuit at the EGR Valve harness connector.
Is the voltage above 5.2 volts?
Yes
- Repair the (K683) EGR Signal circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 4
- Measure the voltage on the (K683) EGR Signal circuit at the EGR Valve harness connector.
- CHECK THE (K683) EGR SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- Turn the ignition off.
- 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.
- Connect the (special tool #10436, Adapter, GPEC Diagnostic).
- Measure the resistance of the (K683) EGR Signal circuit between the EGR Valve harness connector and the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
- Go To 5
No
- Repair the (K683) EGR Signal circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE (K900) SENSOR GROUND CIRCUIT FOR AN OPEN/EXCESSIVE RESISTANCE
- Measure the resistance between ground and the (K900) Sensor Ground circuit at the EGR Valve harness connector.
Is the resistance below 3.0 Ohms?
Yes
- Go To 6
No
- Repair the (K900) Sensor Ground circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Measure the resistance between ground and the (K900) Sensor Ground circuit at the EGR Valve harness connector.
- EGR VALVE
- Reconnect the PCM C2 harness connector.
- Connect a jumper between the (K900) Sensor Ground circuit and the (K683) EGR Signal circuit at the EGR Valve harness connector.
- Turn the ignition on.
- With the scan tool, read active DTCs.NOTE:
The P0405-EGR POSITION SENSOR CIRCUIT LOW 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 7
- CHECK RELATED PCM AND COMPONENT CONNECTIONS
- Perform any Service Bulletins that apply.
- Disconnect all PCM harness connectors.
- Disconnect all related in-line harness connections (if equipped).
- Disconnect the related component harness connectors.
- 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.
- Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
- Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
- Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
- With the scan tool, erase DTCs.
- Test drive or operate the vehicle in accordance with the when monitored and set conditions.
- 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.