DEF SCR SYSTEM (DCU)
5–18
(2) Judgement criteria
Difference between ambient air temperature and engine coolant temperature (from Engine ECU):
>
25
C {77
F} for
10 sec.
3. Reset condition
•
When the starter switch is ON, and when the temperature difference between the DEF pump, the exhaust gas tem-
perature and the engine coolant temperature is within 8
C {46.4
F}, the difference with the engine coolant tempera-
ture should be less than 25
C {77
F}.
4. Indication, warning or system control regulation when the DTC is set.
•
MIL: ON
•
Stop of each temperature sensor failure diagnosis.
5. Symptoms on the vehicle when the DTC is set
<Symptoms on the vehicle due to backup control (fail safe)>
•
–
<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
•
Irregular contact (disconnection or poor fit of connector)
•
Malfunction of ambient air temperature sensor
•
Malfunction of engine coolant temperature sensor
•
Malfunction of exhaust gas temperature sensor (SCR inlet)
•
Malfunction of DEF pump temperature sensor
Summary of Contents for 238
Page 201: ...ENGINE CONTROL SYSTEM J08E 4 978 Harness disconnection or short circuit ...
Page 215: ...ENGINE CONTROL SYSTEM J08E 4 992 Malfunction of sensor 2 Malfunction of engine ECU ...
Page 301: ...ENGINE CONTROL SYSTEM J08E 4 1078 8 Estimated failure factors Malfunction of engine ECU ...
Page 709: ...DEF SCR SYSTEM DCU 5 143 8 Estimated failure factors DEF pump pressure sensor malfunction ...