PACCAR MX (2004 Emissions) Fault Code: P1488 EGR Valve Module – Out of Calibration

PACCAR MX (2004 Emissions) Fault Code: P1488 EGR Valve Module – Out of Calibration

SET CONDITIONS:
The EGR valve module (L095) detects that either:
1. The closed (0%) position is out of range or
2. An internal check routine of the EGR valve module fails to complete successfully.

DIAGNOSTIC CONDITION:
This diagnosis runs after the ignition is keyed ON.

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to INACTIVE if the fault is no longer detected after a key cycle.

REPAIR VERIFICATION:
1. Clear the DTCs.
2. Test drive or operate the vehicle to meet the diagnostic conditions and set conditions.
3. Did the DTC come back?
– No, repair successful.
– Yes, repair unsuccessful.

POSSIBLE CAUSES:
1. E-CAN communication issue
2. Bent actuator lever, valve lever, or connection rod
3. High friction or sticking EGR valve bearings or mechanism
4. Blocked EGR valve

ADDITIONAL INFORMATION:
1. Each time the ignition is keyed ON, the EGR valve compares its closed position (0%) to an ex-factory stored value. If the difference between this ex-factory value and the actual value is higher than the threshold, P1488 is activated.

2. When this DTC is ACTIVE, the actuator motor is switched OFF and the EGR valve is fully closed (0% position).

3. The engine torque is reduced after 10 hours of engine operation.