DTC 2-4-1 EGR System Flow Malfunction

2-4-1 EXHAUST GAS RECIRCULATION SYSTEM, FLOW MALFUNCTION

Precondition for DTC
^ In order for the Exhaust Gas Recirculation (EGR) diagnosis to be active, it is necessary for (a) the car to be started at an Engine Coolant Temperature (ECT) higher than -1O°C (14°F), (b) the ECT to be higher than +80°C (176°F) when the engine was switched off the previous time, (c) battery voltage to be above 12 Volts and (d) the ECT sensor to be undamaged. If voltage across the EGR temperature sensor is not reduced when the ECM sends out a control signal to the EGR controller, the ECM interprets this as system blockage and DTC 2-4-1 is set.

Substitute values
^ Long term fuel trim inhibited.
^ Idle air trim inhibited.
^ Only initial charge pressure is permitted.

Fault sources
^ Signal lead short circuited to voltage.
^ Break in signal or voltage lead.
^ Loose connection or contact resistance in connectors.
^ Defective vacuum hoses.
^ Defective EGR controller.
^ Clogged EGR pipe.
^ Defective EGR valve.

Fault symptoms
^ Poorer performance from initial charge pressure limit.