PACCAR MX (2004 Emissions) Fault Code: P0315 Cylinder Unbalance – Detected

Description

PACCAR MX (2004 Emissions) Fault Code: P0315 Cylinder Unbalance – Detected

SET CONDITIONS:
The PCI ECU (D420) detects an imbalance for more than 500 crankshaft revolutions.

DIAGNOSTIC CONDITION:
This diagnostic runs 30 seconds after the engine has started and when the engine is running at a steady speed and load between 600 and 1900 rpm.

RESET CONDITION:
This DTC changes to inactive when the fault is no longer detected. To validate the repair, drive the vehicle until the coolant temperature is at least 70°C [158°F]. Once the minimum target temperature has been reached, perform several low to higher speed accelerations with moderate engine load. Also perform high-load to low-load transitions. This activity should be conducted within the range of 15 km/h [10 mph] to 65 km/h [40 mph] for no more than 5 to 8 km [3 to 5 miles].

POSSIBLE CAUSES:
1. Fuel injector failure
2. Mechanical engine failure
3. Damaged flywheel holes

ADDITIONAL INFORMATION:
The detection of cylinder misfiring is based on piston acceleration, converted to crankshaft acceleration, which is directly related to the amount of torque that a cylinder produces. To determine crankshaft acceleration, several measurements are performed by the crankshaft sensor (F552) signal.