ENGINE (J05E)/TROUBLESHOOTING
2–531
DTC: P0422
EN01H02127030602016082
P0422: DOC deterioration
INFORMATION
1.
Technical description
<Description of malfunction>
•
If the DOC is not generating heat or if the DOC is generating heat but temperature does not increase at the DOC
outlet, the engine ECU detects DOC deterioration.
2.
DTC set condition
(1)
DTC detection condition
•
Determined during completion of DPR regeneration with the engine running.
•
The exhaust gas flow rate is 150 kg/h or more.H9
•
The engine revolution is 1000 r/min or more.
•
The fuel injection quantity is 30 mm
3
/st or more.
And, the conditions described below remain for 3 seconds.
•
A change in the engine revolution is 625 r/min/sec or less.
•
A change in the fuel injection quantity is 625 mm
3
/sec/st or less.
•
The vehicle speed is 18.8 mile/h or more.
And, the conditions described below remain for 10 seconds.
•
The predicted detection temperature of the exhaust gas temperature sensor (DPF inlet) calculated by the
engine ECU is 450
C {842
F} or more.
(2)
Judgement criteria
•
The temperature detected at the exhaust gas temperature sensor (DPF inlet) remains 385
C {725
F} or less
for 30 seconds.
3.
Reset condition
•
Immediately after normal status is resumed
4.
Indication, warning or system control regulation when the DTC is set.
•
MIL: ON
•
SVS light: OFF
5.
Symptoms on the vehicle when the DTC is set
<Symptoms on the vehicle due to backup control (fail safe function)>
•
–
<Symptoms on the vehicle due to malfunction>
•
–
6.
Pre-inspection work
•
Check that the battery voltage is in the normal range.
7.
After-inspection work
•
Clear all past DTCs.
•
Check that no DTC is detected after test drive.
8.
Estimated failure factors
•
DOC deterioration caused by use of low-grade fuel
•
Contamination in the sensing area of the exhaust gas temperature sensor (DPF inlet), improper installation of sen-
sors