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P0405






P0405-EGR POSITION SENSOR CIRCUIT LOW

Special Tools:










For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
With the ignition on. Battery voltage above 10.0 Volts.

- Set Condition:
Exhaust Gas Recirculation (EGR) Position Sensor Signal is less than the minimum acceptable voltage. One trip Fault.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, select View DTCs. Record DTC and Freeze Frame information.
3. Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.

WARNING: The normal operating temperature of the EGR system is very high. Never work around or attempt to service any part of the EGR system until it has cooled. Failure to follow these instructions can result in possible serious or fatal injury.

NOTE: Attempt to operate the vehicle under conditions similar to which the DTC was set.

NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set.

4. With the scan tool, select View DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. (F856) 5-VOLT SUPPLY CIRCUIT




1. Turn the ignition off.
2. Disconnect the EGR Solenoid harness connector.
3. Ignition on, engine not running.
4. Measure the voltage of the (F856) 5-volt Supply circuit in the EGR Solenoid harness connector.

Is the voltage between 4.5 to 5.2 Volts?

Yes

- Go To 3

No

- Go To 7

3. (K34) EGR POSITION SENSOR SIGNAL CIRCUIT SHORTED TO GROUND




1. Turn the ignition off.
2. Disconnect the C2 PCM harness connector.
3. Measure the resistance between ground and the (K34) EGR Position Sensor Signal circuit in the EGR Solenoid harness connector.

Is the resistance below 100 Ohms?

Yes

- Repair the short to ground circuit in the (K34) EGR Position Sensor Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 4

4. (K34) EGR SENSOR SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT




1. Measure the resistance between the (K34) EGR Position Sensor Signal circuit and (K900) Sensor ground circuit in the EGR Solenoid harness connector.

Is the resistance below 100 Ohms?

Yes

- Repair the short between the (K900) Sensor ground and the (K34) EGR Position Sensor Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 5

5. EXCESSIVE RESISTANCE IN THE (K34) EGR SIGNAL CIRCUIT





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 PCM Pinout Box (8815A) to perform diagnosis.

1. Measure the resistance of the (K34) EGR Signal circuit between the Exhaust Gas Recirculation Valve harness connector and the appropriate terminal of PCM Pinout Box.

Is the resistance below 5.0 Ohms?

Yes

- Go To 6

No

- Repair the excessive resistance in the (K34) EGR Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

6. EXHAUST GAS RECIRCULATION VALVE
1. Turn the ignition off.
2. Connect the C2 PCM harness connector.
3. Turn the ignition on.
4. With the scan tool, read the Exhaust Gas Recirculation Valve signal voltage.

NOTE: The sensor voltage should be approximately 5.0 Volts (plus or minus.1 of a volt) with the connector disconnected.

Does the scan tool display the voltage as described above?

Yes

- Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors. Replace the EGR Valve Assembly if no problems were found with the connectors.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 9

7. (F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND




1. Turn the ignition off.
2. Disconnect the C1 PCM harness connector.
3. Measure the resistance between ground and the (F856) 5-volt Supply circuit in the EGR Solenoid harness connector.

Is the resistance below 100 Ohms?

Yes

- Repair the short to ground in the (F856) 5-volt Supply circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 8

8. (F856) 5-VOLT SUPPLY CIRCUIT OPEN





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 PCM Pinout Box (8815A) to perform diagnosis.

1. Measure the resistance of the (F856) 5-volt Supply circuit from the EGR Solenoid harness connector to the appropriate terminal of PCM Pinout Box.

Is the resistance below 5.0 Ohms?

Yes

- Go To 9

No

- Repair the open in the (F856) 5-volt Supply circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

9. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the EGR Solenoid Assembly and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Solenoid and the Powertrain Control Module connectors.
4. Search for any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.