Dtc: U029E: Engine Ecu Can Communication (Nox Sensor (Scr Downstream)) - Hino 238 Workshop Manual

DTC: U029E
U029E: Engine ECU CAN communication (NOx sensor (SCR downstream))
INFORMATION
%J1
Twist
CAN TMN
(K6W)
%J4
F2F
(CANL) (K6V)
F2E
(CANH)
Twist
Twist
Engine
ECU
1. Technical description
• NOx sensor 2 (control part) is connected via the DCU and CAN communication.
<Description of malfunction>
• CAN communication failure is detected.
2. DTC set condition
(1) DTC detection condition
• Starter switch ON.
• Engine ECU power supply voltage is in the range of 11 V to 16 V.
(2) Judgement criteria
• Disconnection between NOx sensor 2 (SCR downstream) and CAN bus line is detected for 3 seconds.
3. Reset condition
• Immediately after normal operation is restored.
4. Indication, warning or system control regulation when the DTC is set.
• MIL: ON
• Diag lamp: OFF
5. Symptoms on the vehicle when the DTC is set
<Symptoms on the vehicle due to backup control (fail safe function)>
–
•
<Symptoms on the vehicle due to malfunction>
• Multiple DTC are detected because of failure of main CAN communication harness.
ENGINE CONTROL SYSTEM (J08E)
%J6
Twist
(LEZ)
L
%J7
H (LEY)
Twist Twist
EGR VNT
Controller Controller
#SF
Twist
(LEZ)
#SF
#SD
#SD
(LEY)
Twist
Common rail
Twist
%KL
(7)
%KM
(6)
Twist
DEF
Sensor
EN01H16F01030F03001164
Common rail
CAN J/C3
%JV %JZ
(3) (7)
L #AP #AP
%JQ
H %JU #AN #AN
(6)
(2)
Twist
Twist
NOx NOx
sensor 1 sensor 2
CAN J/C1
%KE
(3)
L
%KF
H (2)
Twist
BCU
SAPH16F010301035
4–1325
Twist
DCU