PACCAR MX (2004 Emissions) Fault Code: P1026 BPV Actuator – Out of Calibration

Description

PACCAR MX (2004 Emissions) Fault Code: P1026 BPV Actuator – Out of Calibration

SET CONDITIONS:
The BPV valve (L096) detects that the open (100%) position is out of range.

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

CORRESPONDING OBD READINESS MONITOR:
None

RESET CONDITION:
This DTC changes to INACTIVE after the ignition is keyed OFF for at least 15 seconds and keyed ON again and the error is no longer detected.

REPAIR VERIFICATION:
1. Clear all 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. Incorrectly installed link rod
2. Bent actuator lever and/or link rod
3. Broken return-spring of the valve mechanism
4. Incorrect actuator power-supply wiring
5. High friction or sticking BPV valve bearings or mechanism
6. Blocked BPV valve

ADDITIONAL INFORMATION:
IMPORTANT: When this DTC is present, traces of lubrication oil may be visible at the compressor side of the VTG turbocharger. This does not necessarily indicate a failing turbocharger.

1. The open (100%) position of the BPV valve is checked by the actuator and compared with an ex-factory stored value.
2. The actuator motor is switched OFF and the BPV valve is fully opened (100% position) with this DTC ACTIVE.
3. Engine torque is reduced after 10 hours of engine operation.