Hino 238, Workshop Manual

Page: 719 / 919

DEF SCR SYSTEM (DCU) 5–153
DTC: P204D
EN01H16F02040F03001034
DTC: P204D DEF pressure sensor - out of range (Out of range high)
INFORMATION
1. Technical description
• The pressure sensor in the DEF pump is used to confirm the pressure in the DEF pump.
•
A short-circuit or disconnection in the DEF pump pressure sensor is detected with the DCU.
<Description of malfunction>
•
Failure of the pressure sensor in the DEF pump is detected.
2. DTC set condition
(1) DTC detection condition
Starter switch ON.
(2) Judgement criteria
DEF pump pressure sensor circuit voltage
>
4.75 V for more than 0.4 sec.
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.
Supply module
(DEF pump)
DCU
LFQ
(PSR+)
LFR
LGD
(PSRS)
(PSR+)
(PSRS)
LFP LGF
(PSR-)
(PSR-)
LFJ
(PMP+)
LFL
LG8
(PMPS)
(PMP+)
(PMPS)
LFK LGA
(PMP-)
(PMP-)
LFM LGB
(PMV+)
(PMV+)
LFN LGC
(PMV-)
(PMV-)
LGE
LG9
SAPH16F020400100