P2BAC - NOX EXCEEDENCE - DEACTIVATION OF EGR

The Exhaust Gas Recirculation System sends a part of the burned gases to the engine induction. Most of the nitrogen oxide is removed there. This system has some built-in sensors. Through these sensors, the PCM (Powertrain Control Module) checks the pressures in the Diesel Particulate Filter (DPF) to reduce soot particles.

Some vehicles have a built-in NOx trap to stop nitrogen oxide particles. They are removed during the regeneration process of the Diesel Particulate Filter. When this system does not work properly, fuel consumption is affected and the DPF ends up blocked.

If the PCM detects pressure levels outside the parameters established by the manufacturer due to excessive NOx accumulation, the EGR system will be deactivated, and the P2BAC OBDII diagnostic code will be set.

• Check Engine light ON.
• Loss of fuel efficiency.
• Excessive tailpipe emissions.
• Lower engine power.

The reasons for storing the P2BAC OBD2 fault code are:

• The wiring harness and connectors associated with the Exhaust Gas Recirculation Sensor circuit may have an open circuit.
• The Diesel Exhaust Fluid may be low or incorrect.
• The EGR sensor may be faulty.
• The DPF may be clogged.

To troubleshoot the P2BAC OBDII DTC P2BAC, try this:

• Consult the Tecnical service Billetins (TSB) to find useful information associated with the code.
• We also recommend using a scanner to check no other codes related to the emission system are stored.
• Check the electrical components related to the EGR Sensor are in proper condition. If you find irregularities such as damaged wires or a faulty connector, make repairs as required.
• Check the Diesel Exhaust Fluid level is correct. If this value does not meet the requirements, verify that it is not due to leaks in the lines through which the fluid circulates. Make the necessary corrections.
• Use a DVOM to check the voltage and resistance of the EGR sensor. If the reading obtained does not match the values provided by the manufacturer, you should check the good condition of the electrical connections. If no deficiencies are found in the connections, the sensor is damaged, which requires its replacement.