P0405-EGR POSITION SENSOR CIRCUIT LOWFor a complete wiring diagram Refer to Section 8W.When Monitored:With the ignition on. Battery voltage above 10.0 volts.Set Condition:EGR Position Sensor Signal is less than 0.1 of a volt. One trip Fault.
Possible Causes(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND(F856) 5-VOLT SUPPLY CIRCUIT OPEN(K34) EGR SIGNAL CIRCUIT SHORTED TO GROUND(K34) EGR SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUITEGR POSITION SENSORPCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).Diagnostic Test1.EGR POSITION SENSOR BELOW 0.2 OF A VOLTIgnition on, engine not running.With a scan tool, read the EGR Position Sensor voltage.Is the voltage below 0.2 of a volt?YesGo To 2NoGo To 92.(F856) 5-VOLT SUPPLY CIRCUITTurn the ignition off.Disconnect the EGR Solenoid harness connector.Ignition on, engine not running.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?YesGo To 3NoGo To 63.EGR POSITIONWith the scan tool, monitor the EGR Position Sensor voltage.Is the voltage above 4.5 volts?YesReplace the EGR Solenoid Assembly.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 44.(K34) EGR SIGNAL CIRCUIT SHORTED TO GROUNDTurn the ignition off.Disconnect the C2 PCM harness connector.Measure the resistance between ground and the (K34) EGR Signal circuit in the EGR Solenoid harness connector.Is the resistance below 100 ohms?YesRepair the short to ground circuit in the (K34) EGR Signal circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 55.(K34) EGR SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUITMeasure the resistance between the (K34) EGR Signal circuit and (K900) Sensor ground circuit in the EGR Solenoid harness connector.Is the resistance below 100 ohms?YesRepair the short between the (K900) Sensor ground and the (K34) EGR Signal circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 86.(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUNDTurn the ignition off.Disconnect the C1 PCM harness connector.Measure the resistance between ground and the (F856) 5-volt Supply circuit in the EGR Solenoid harness connector.Is the resistance below 100 ohms?YesRepair the short to ground in the (F856) 5-volt Supply circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 77.(F856) 5-VOLT SUPPLY CIRCUIT OPENDo not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special
Tool #8815 to perform diagnosis.Measure the resistance of the (F856) 5-volt Supply circuit from the EGR Solenoid harness connector to the appropriate terminal of special tool #8815.Is the resistance below 5.0 ohms?YesGo To 8NoRepair the open in the (F856) 5-volt Supply circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)8.PCMBefore continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.Were there any problems found?YesRepair as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoReplace and program the Powertrain Control Module per Service Information.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)9.EGR POSITION SENSOR SWEEP The engine will run rough and possibly stall in the following test. Feather the accelerator pedal to keep the engine from stalling.Start the engine.With the scan tool, enter 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?YesRefer to the INTERMITTENT CONDITION Diagnostic Procedure.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoReplace the EGR Solenoid Assembly.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)