2013 PACCAR MX-13 – P0069 Boost pressure – Data erratic, intermittent, or incorrect at ignition on

Fault code information

2 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)

Diagnostic condition

This diagnostic runs:
* when the ignition is keyed on (NO engine start), and
* ambient temperature is more than -20°C [-4°F]

Set condition of fault code

The PCI ECU (D420) detects that the measured boost pressure differs by more than 0.17 bar [2.5 psi] from the average of other pressure sensor readings on the engine for more than 5 seconds.

Reset condition of fault code

To validate the repair, key on the ignition (NO engine start) and wait for 10 seconds to allow the system to power up and the diagnostics to run.

Electrical diagram(s)

D420 PCI ECU
F802 Boost pressure sensor

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

Boost pressure sensor deviation

Additional information

For this diagnostic, the boost pressure sensor (F802) reading is compared with an average of other engine pressure sensor readings.

Leave a Reply

Your email address will not be published. Required fields are marked *