Circuit Description

See CODE P0401  - INSUFFICIENT EXHAUST GAS RECIRCULATION (EGR) FLOW DETECTED. Code is set when intake manifold absolute pressure is greater than the value calculated by the ECM while the EGR system is on and misfiring is detected during idling. Possible causes are:

• EGR valve stuck open.
• EGR Vacuum Switching Valve (VSV).
• MAP sensor.
• ECM.