DTC P0401: Insufficient Exhaust Gas RECIRCULATION (EGR) Flow Detected: Notes

CAUTION: If ECM replacement is instructed in following testing, always ensure ECM connectors and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction.

NOTE: If DTC P0105, P0106 and P0401 are output simultaneously, perform DTC P0105: MANIFOLD ABSOLUTE PRESSURE (MAP)/BAROMETRIC PRESSURE SENSOR CIRCUIT test first. If DTC P0401 and P0402 are output simultaneously, perform DTC P0402: EXCESSIVE EXHAUST GAS RECIRCULATION (EGR) FLOW DETECTED test before performing DTC P0401 test.