Monitor Description

P0400-00 

During fuel cut (vehicle being driven with idle ON), when the change in intake manifold pressure when the EGR valve assembly is operating and not operating is insufficient, the ECM determines that the EGR valve is stuck and stores DTC P0400-00 and illuminates the MIL.

P0401-9C 

During fuel cut (vehicle being driven with idle ON), when the change in intake manifold pressure when the EGR valve assembly is operating and not operating is insufficient, the intake manifold pressure is less than the threshold when the EGR valve assembly is not operating, the ECM determines that the flow through the EGR valve is hindered and stores DTC P0401-9C and illuminates the MIL.

P0402-9B 

During fuel cut (vehicle being driven with idle ON), when the change in intake manifold pressure when the EGR valve assembly is operating and not operating is insufficient, the intake manifold pressure is more than the threshold when the EGR valve assembly is not operating, the ECM determines that the flow through the EGR valve is excessive and stores DTC P0402-9B and illuminates the MIL.