DEF SCR SYSTEM (DCU)
5–225
DTC: P20B1
EN01H16F02040F03001047
DTC: P20B1 DEF tank heater valve - circuit (Open load)
INFORMATION
1. Technical description
•
DCU detects malfunctions based on the coolant cut off valve (DEF tank heater valve) circuit voltage.
<Description of malfunction>
•
Malfunction of coolant cut off valve (DEF tank heater valve) is detected.
2. DTC set condition
(1) DTC detection condition
Starter switch ON.
Coolant cut off valve (DEF tank heater valve) duty
>
0%
(2) Judgement criteria
Coolant cut off valve (DEF tank heater valve) voltage is more than 2.7 V and less than 5 V for 0.5 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 failure lamp: ON.
•
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)>
•
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
•
Harness disconnection or short-circuit
•
Looseness or unsteady contact of connectors
•
Coolant cut off valve (DEF tank heater valve) malfunction
Twist
Twist
DCU
Coolant cut
off valve
(DEF tank
heater valve)
LDU
(+)
LDV
LFA
(E)
(WMW+)
(WMV-)
LFB
SAPH16F020400149
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 ...