2013 PACCAR MX-13 – P0263 Cylinder 1 – Torque contribution too low

Fault code information

1 trip MIL
3 drive cycle recovery
Readiness group – Fuel system
Freeze frame type – Fuel

Description of component(s)

Description, injector (B421, B422, B423, B424, B425, B426)

The fuel injector injects fuel into the combustion chamber.


The amount of fuel injected depends on the duration of the injector solenoid activation in combination with the rail pressure. The longer the solenoid is activated by the PCI ECU at the same rail pressure, the more fuel is injected.

Minimum opening pressure

The injectors do not open below a rail pressure of 180–190 bar [2610–2756 psi].

Injector codes

Every fuel injector is calibrated during production to compensate for any production tolerances. An injector calibration code is present on the housing and connector of the injector. These injector codes must be (re)programmed with DAVIE if one or more injectors have been replaced or fitted in another position, or if the PCI ECU is replaced.

Description, crankshaft sensor (F552)

Effect on the system:
* registration of crankshaft speed
* registration of crankshaft position
* calculation of the engine speed
* synchronization during starting (together with camshaft signal)
* diagnostic checks on cylinder misfire and cylinder contribution
* monitoring correct alignment between the crankshaft and the camshaft
* back up for camshaft signal (F558)

Description, camshaft sensor (F558)

The pulse wheel is attached to the inlet camshaft.

Effect on the system:
* Cylinder detection
* Synchronization during starting (together with crankshaft signal)
* Monitors correct alignment between the crankshaft and the camshaft
* Back up function for the calculation of the engine speed and crankshaft position in case the absence        of the crankshaft signal (F552).

Description, solenoid valve engine brake cylinder 1-6 (L147–L152)

Location of component(s)

Solenoid valve injector cylinder 1 (B421)

Diagnostic condition

This diagnostic runs when the engine is running at a steady speed and load, and the vehicle speed is steady.

Set condition of fault code

The PCI ECU (D420) detects that the combustion contribution of cylinder 1 is lower relative to the other cylinders.

Reset condition of fault code

This DTC changes to inactive when the fault is no longer detected.

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