Hino 238, Workshop Manual

Page: 669 / 919

DEF SCR SYSTEM (DCU) 5–103
DTC: P202E
EN01H16F02040F03001024
DTC: P202E Reductant Delivery Performance
INFORMATION
1. Technical description
•
The amount of added DEF is diagnosed as abnormal.
• The amount of added DEF is controlled by the DEF pressure and the opening of the DEF injector.
<Description of malfunction>
• Failure of DEF injector at system startup is detected.
2. DTC set condition
(1) DTC detection condition
<At system start up>
The engine is ON.
Exhaust gas temperature sensor (SCR inlet)
>
150

C {302

F}
DEF pump pressure is stable for 8 sec. when it is between 850 kPa {123 psi} and 950 kPa {138 psi}.
(2) Judgement criteria
<At system start up>
Pressure line check start: DEF pump speed: keep and DEF injector: full open
If DEF pressure is
>
750 kPa {108 psi} after 4 sec. from DEF injector open, failure counter is count up.
When Failure counts
≥
22, DTC is detected.
3. Reset condition
•
After having restored to the normal conditions.
4. Indication, warning or system control regulation when the DTC is set.
•
MIL: ON
• SCR system malfunction lamp: ON
•
DEF injection is stopped.
• NOx purification function is stopped.
•
Output restricted instantaneously.
• If malfunction does not improve within 50 min.: vehicle speed is restricted.
Back flow Line Pressure Line
Inside the muffler
DEF Injector
DEF Tank
Suction Line
DEF Pump
Pressure sensor
P
SAPH16F020400070