P0407 - EXHAUST GAS RECIRCULATION SENSOR "B" CIRCUIT LOW
Description of DTC code P0407
The PCM (Powertrain Control Module) controls the EGR (Exhaust Gas Recirculation) Valve, which is in charge of the exhaust emissions. Thus, it achieves the elimination of the same by being incorporated into the cylinders through the air/fuel mixture.
In some cases, the EGR Valve is vacuum controlled by the Powertrain Control Module. The PCM activates a solenoid to open the valve under a vacuum. In other cases, the valve is electronically controlled and monitored by a series of ground signal and voltage supply wires.
When the PCM detects voltage levels out of the established parameters indicating a low circuit, the DTC P0407 OBD2 will be set.
Symptoms of fault code P0407
- Check Engine light ON.
- Low fuel consumption.
- Engine stability failures.
Causes of OBD2 P0407
Reasons for storing the P0407 OBDII diagnostic code:
- Possibly there is a short to ground in the EGR Sensor reference signal.
- The Exhaust Gas Recirculation Sensor circuit wiring harness may be faulty.
- The Exhaust Gas Recirculation Valve may be clogged or damaged.
Possible solutions of the DTC code P0407
Steps to troubleshoot the P0407 OBD2 fault code:
- Check the wiring harness associated with the Exhaust Gas Recirculation Sensor circuit for defects such as wear or burns. Repair as required.
- Use a scanner to check the operation of the EGR valve. If it responds correctly, i.e. opens and closes, the problem is intermittent due to moisture factors.
- Use a multimeter and check that the Exhaust Gas Recirculation Valve is receiving the 5 volts reference and feedback. If the reading differs from the set value, check for proper electrical connections. Make any necessary repairs.
- If after performing the above checks you still get the code P0407, the valve is possibly faulty, replace it.