Diagnostic Trouble Codes
Group 30: Electrical system
138
Circuit description
The task of the pressure limiting valve (safety valve)
is to protect the system from excess pressure. The
valve opens and reduces the fuel pressure (rail pres-
sure) by releasing fuel to the return pipe as neces-
sary. The valve is a two-stage valve. Stage one
opens at about 190 MPa (1900 bar / 27557 psi) and
stage 2 maintains the pressure at about 60 MPa (600
bar / 8702 psi). If the MPROP valve* has been dam-
aged and gives full flow, for example, the pressure re-
lease valve reduces the fuel flow to about 60 MPa
(600 bar / 8702 psi).
* NOTE!
MPROP valve = Magnetically controlled pro-
portional valve.
Fault tracing
FMI 0
Conditions for fault code:
Leakage detected in rail pressure release valve, open
mode.
Possible reason:
•
Rail pressure controller out of range.
•
Faulty rail pressure release valve.
Suitable action:
1.
Check function of rail pressure sensor.
2.
Change the rail pressure release valve.
