DTC P0405: EGR Position Sensor Low: Testing
- Turn ignition on, engine not running. With the DRBIII®, read the EGR Position Sensor voltage. Is the voltage below 0.2 volt? If yes, go to next step. If no, go to step 10.
- Turn the ignition off. Disconnect the EGR Solenoid harness connector. Turn ignition on, engine not running. Measure the voltage of the 5-Volt Supply circuit in the EGR Solenoid harness connector. Is the voltage between 4.5 and 5.2 volts? If yes, go to next step. If no, go to step 7.
- With the DRBIII®, monitor the EGR Position Sensor voltage. Is the voltage above 4.5 volts? If yes, replace the EGR Solenoid Assembly. If no, go to next step.
- Turn the ignition off. Disconnect PCM harness connectors. Measure the resistance between ground and the EGR Sensor Signal circuit at the EGR Solenoid harness connector. Is the resistance below 100 ohms? If yes, repair the short to ground in the EGR Sensor Signal circuit. If no, go to next step.
- Measure the resistance between the EGR Sensor Signal circuit and the Sensor Ground circuit at the EGR Solenoid harness connector. Is the resistance below 100 ohms? If yes, repair the short to EGR Sensor Ground circuit in the EGR Sensor Signal circuit. If no, go to next step.
- There are no possible causes remaining, replace PCM. Program the new PCM. See PROGRAMMING .
- Turn the ignition off. Ensure the EGR Solenoid is disconnected. Disconnect PCM harness connectors. Measure the resistance between ground and the 5-Volt Supply circuit at the EGR Solenoid harness connector. Is the resistance below 100 ohms? If yes, repair the short to ground in the 5-Volt Supply circuit. If no, go to next step.
- Measure the resistance of the 5-Volt Supply circuit from the EGR Solenoid harness connector to the appropriate terminal at Miller Special Tool. Is the resistance below 5.0 ohms? If yes, go to next step. If no, repair the open in the 5-Volt Supply circuit.
- There are no possible causes remaining, replace PCM. Program the new PCM. See PROGRAMMING .
- Start the engine. The engine will run rough and possibly stall in the following test. Feather the accelerator panel to keep the engine from stalling. With the DRBIII®, enter Engine System Test and then EGR System Test. Push the 4=VARIABLE function. Monitor the EGR voltage while slowly pushing the up arrow. Is the voltage change smooth? If yes, go to next step. If no, replace the EGR Solenoid Assembly.
- The conditions that set the DTC are not present at this time. The following may help in identifying the intermittent condition. With the engine running at normal operating temperature, monitor the DRBIII® parameters related to the DTC while wiggling the wiring harness. Look for parameter values to change and/or a DTC to set. Review the DRBIII® Freeze Frame information. If possible, try to duplicate the conditions under which the DTC was set. Refer to any Technical Service Bulletins (TSB) that may apply. Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals. Were any of the above conditions present? If yes, repair as necessary. If no, test is complete.
NOTE:
Before continuing, check the PCM harness connectors for corrosion, damage or terminal push out. Repair as necessary.
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. Use Miller Special Tool (8815) when performing diagnosis at PCM harness connectors.
NOTE:
Before continuing, check the PCM harness connectors for corrosion, damage or terminal push out. Repair as necessary.
WARNING:
When the engine is operating, do not stand in a direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing.