P2425 - EXHAUST GAS RECIRCULATION COOLING VALVE CONTROL CIRCUIT / OPEN

The Exhaust Gas Recirculation System (EGR) is built into diesel engine vehicles. The function of this system is to send exhaust gases to the engine induction system where they are converted to air. A cooling valve is included in the EGR, which controls the flow of engine coolant.

The Powertrain Control Module (PCM) receives constant signals from the EGR Coolant Temperature Sensor (ECT) and the EGR Cooler Temperature Sensor to determine the times at which the cooling valve opens and closes. If the voltages from these sensors are inconsistent with those programmed into the PCM, the P2425 OBDII diagnostic code will be stored and the Check Engine service lamp will illuminate.

• MIL light illuminated.
• Increased engine temperature.
• Decreased fuel efficiency.
• Excessive exhaust smoke.

The reasons for the P2425 OBD2 fault code being set are:

• There may be a short in the EGR System reference signal.
• Engine coolant levels may be low.
• Possibly the Exhaust Gas Recirculation Valve is faulty.
• The Coolant Temperature Sensor could be bad.

To troubleshoot DTC P2425 OBDII take the following steps

• Consult the Technical Service Bulletins (TSB).
• Inspect the cables and connectors of the Exhaust Gas Recirculation System and check that they are in good condition. If one of these has damage that causes an open circuit, you should make the appropriate corrections.
• Check that the engine coolant level meets the requirements for proper operation. If you observe levels below the necessary, verify that it is not due to leaks. Make the corresponding adjustments.
• Check the EGR valve for blockages or obstructions. If such a condition is found, repairs should be made as necessary.
• Use a DVOM to test the coolant temperature sensor for voltage and resistance. If the reading is not within the parameters set by the manufacturer, replace the sensor.