DTC P0401 Or DTC P0402: Condition

DTC P0401 is set when there is a difference in intake manifold absolute pressure, when Exhaust Gas Recirculation (EGR) valve is opened and when EGR valve is closed is less than specified value.

DTC P0402 is set when there is a difference in intake manifold absolute pressure, when EGR valve is opened and when EGR valve is closed is more than specified value. MIL is illuminated when Engine Control Module (ECM) detects malfunction during 2 consecutive drive cycles. Possible causes are:

• ECM malfunction.
• EGR valve malfunction.
• EGR passage restricted.
• Manifold Absolute Pressure (MAP) sensor malfunction.