DTC 1-5-4 EGR System Leakage

1-5-4 EXHAUST GAS RECIRCULATION SYSTEM LEAKAGE

Condition(s) for DTC
^ Engine cold (temperature below 65°C / 150°F).
^ Rising temperature sensor indication (falling signal level).
^ If the ICM detects that the EGR temperature sensor signal level is varying by more than the predetermined (temperature-dependent) values before the engine temperature has reached 65°C (150°F), it will interpret the condition as indicating an EGR flow when none should be present, and the DTC will be recorded.

Substitute value
^ None.

Fault source(s)
^ Faulty (leaking) EGR valve.
^ Faulty signal to EGR controller.
^ Faulty EGR controller.
^ Poor ground connection.
^ Faulty coolant thermostat.

Fault symptom(s)
^ Engine may idle unevenly.

NOTE: Take care when removing the yellow and white hoses. Grip and twist hose rubber connector ends only, not the plastic hose itself. The hoses may break or crack if pulled from their connections.