P0405
P0405-EGR POSITION SENSOR CIRCUIT LOWP0405 - EGR Position Sensor Circuit Low:
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 position sensor signal circuit shorted to ground
- (K34) EGR position sensor signal circuit shorted to the (K900) sensor ground circuit
- EGR position sensor
- PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview
Diagnostic Test
1. EGR POSITION SENSOR BELOW 0.2 OF A VOLT
Ignition on, engine not running.
With a scan tool, read the EGR Position Sensor voltage.
Q: Is the voltage below 0.2 of a volt?
YES: Go To 2
NO: Go To 9
2. (F856) 5-VOLT SUPPLY CIRCUIT
Turn 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.
Q: Is the voltage between 4.5 to 5.2 volts?
YES: Go To 3
NO: Go To 6
3. EGR POSITION
With the scan tool, monitor the EGR Position Sensor voltage.
Q: Is the voltage above 4.5 volts?
YES: Replace the EGR Solenoid Assembly. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 4
4. (K34) EGR POSITION SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Measure the resistance between ground and the (K34) EGR Position Sensor Signal circuit in the EGR Solenoid harness connector.
Q: 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 5
5. (K34) EGR SENSOR SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
Measure the resistance between the (K34) EGR Position Sensor Signal circuit and (K900) Sensor ground circuit in the EGR Solenoid harness connector.
Q: 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 8
6. (F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Turn 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.
Q: 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 7
7. (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 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.
Q: Is the resistance below 5.0 Ohms?
YES: Go To 8
NO: Repair the open in the (F856) 5-volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
8. PCM
NOTE: Before 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.
Q: 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
9. EGR POSITION SENSOR SWEEP
NOTE: 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.
Q: Is the voltage change smooth?
YES: Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Component Tests and General Diagnostics
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Replace the EGR Solenoid Assembly. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test