Hino 238, Workshop Manual

Page: 692 / 919

DEF SCR SYSTEM (DCU) 5–126
DTC: P2047
EN01H16F02040F03001029
DTC: P2047 DEF injector - functional
INFORMATION
1. Technical description
•
DEF dosing valve is controlled by DCU.
• Operation of the DEF dosing valve is checked by DCU based on the circuit current waveform.
<Description of malfunction>
• DEF injector failure is detected.
2. DTC set condition
(1) DTC detection condition
The engine is ON.
DEF injector duty cycle:
>
0%, and DEF Pressure
>
350 kPa {51 psi}, and 9 V
<
Battery
<
16 V, and Time elapsed
since DEF injector opening
≤
0.0025 sec.
(2) Judgement criteria
Second order differential in the DEF injector circuit current waveform: Below 80 A/sec^2 detected 50 times consecu-
tively.
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.
•
If malfunction does not improve within 500 miles: engine output is restricted.
• If malfunction does not improve within 2,000 miles: vehicle speed is restricted.
5. Symptoms on the vehicle when the DTC is set
<Symptoms on the vehicle due to backup control (fail safe function)>
•
Exhaust gas purification function has deteriorated.
• Engine output is insufficient (when malfunction does not improve within 500 miles).
•
Vehicle does not speed up (when malfunction does not improve within 2,000 miles).
<Symptoms on the vehicle due to malfunction>
•
–
6. Pre-inspection work
• Check if the battery voltage is in the normal range.
7. After-inspection work
• Clear all past DTCs.
•
Check if no DTC is stored after test drive.
8. Estimated failure factors
• DEF injector: Malfunction of injector
* Clogging of crystallized DEF is suspected.
Dosing
module
(DEF
injector)
LG6
(DMH)
LG7
LF8
(DML)
(DMH)
(DML)
LF9
Twist Twist
DCU
SAPH16F020400081