Fault code information
2 trip MIL
3 drive cycle recovery
Readiness group – None
Freeze frame type – Comprehensive
Description of component(s)
Description, pressure sensor after BPV (F823)
The exhaust gas pressure after the BPV valve is measured by the sensor (1) via a steel tube (2).
Effect on the system:
* Correction of the NOx sensor before the catalyst signal
A higher measured exhaust gas pressure after the BPV valve results in lower calculated NOx emissions by the engine.
* Calculates the exhaust gas temperature before the turbine
Lower measured exhaust gas pressure after the BPV valve results in higher calculated exhaust gas temperature before the turbine.
Location of component(s)
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 pressure after BPV differs by more than 0.07 bar [1 psi] from the average of other pressure sensors 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.
Handle connectors and pins with care and use matching measuring probes.
Component & wiring check, ECU (D420)
* Key off the ignition.
* Disconnect connector F823
* Measure on the front side of wiring harness connector F823
Pressure sensor after BPV deviation
For this diagnostic, the pressure sensor after BPV (F823) reading is compared with an average of other pressure sensor readings on/off the engine.