2013 PACCAR MX-13 – P0108 Boost pressure – Voltage too high or short circuit to supply on ECU (D420) pin (A51)

Fault code information

1 trip MIL
3 drive cycle recovery
Readiness group – None
Freeze frame type – Comprehensive

Description of component(s)

Boost pressure sensor (F802)
The boost pressure is measured in the inlet manifold, near cylinder 1.

Effect on the system
* Determines the smoke limit
A higher measured boost pressure increase results in higher torque for the same smoke level
* Determines soot emissions
A higher measured boost pressure results in lower calculated soot emission by the engine.
* Determines NOx emissions
A higher measured boost pressure results in higher calculated NOx emission by the engine.
* Calculates exhaust gas mass flow used for DEF dosing estimation by the EAS-3 system.
A higher measured boost pressure results in higher calculated exhaust gas mass flow.
* Calculates the temperature after the compressor (VTG turbo charger)
A higher measured boost pressure results in higher calculated temperature after the compressor.
* Calculates the temperature before the turbine.
A higher measured boost pressure results in lower calculated exhaust gas temperature before the             turbine.

Location of component(s)

Set condition

The PCI ECU detects the sensor output voltage is too high.

Reset condition

This fault code will change to inactive immediately after the diagnostic runs and passes.
This fault cannot be cleared from the ECU’s memory. Contact the PACCAR Engine Support Center for further instructions.

Electrical diagram(s)

Technical data

Component check, boost pressure sensor (F802)
This type of component cannot be checked with a multimeter or oscilloscope. Perform the following to assess the component:
* Monitor/test the component with DAVIE
* Perform the wiring check

Component & wiring check, ECU (D420)
Preparation
* Key off the ignition
* Disconnect connector F802
* Measure on the front side of wiring harness connector F802

Possible causes

* Faulty wiring
* Faulty connection
* Faulty sensor

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