Circuit Description
See CODE P0401 - INSUFFICIENT EXHAUST GAS RECIRCULATION FLOW DETECTED . Code is set when Exhaust Gas Recirculation (EGR) gas temperature sensor value is high. Engine not yet at normal operating temperature. Possible causes are:
- EGR valve stuck open.
- EGR Vacuum Switching Valve (VSV).
- EGR VSV open circuit.
- EGR gas temperature sensor short circuit.
- ECM.