FAILURE DIAGNOSIS
1-92
TNV DI Service Manual
DTCs (Diagnostic Trouble Codes) General Description
(5) P1422/4: Failure A with EGR valve (Step Motor C-phase)
DTC Detecting Conditions
Movement at Error occurrence
Estimation of Failure cause/Error condition
• The connector may not be properly connected.
• Wiring defect of the harness
•
The EGR step motor C-phase wiring may be disconnected or short-circuited with GND.
•
The EGR step motor power supply line may be disconnected.
• The EGR step motor may be faulty.
•
Inner wiring of the EGR step motor C-phase may be disconnected or short-circuited with GND.
•
Power supply line in the EGR step motor may be disconnected.
• The E-ECU internal circuitry may be faulty.
DTC
P1422/4
Failure A with EGR valve (Step Motor C-Phase)
1 - Precondition; 2 - Detecting condition(s);
3 - Flashing pattern of failure indicator
Check points
1. Key switch ON.
2. Make an assessment logically as to followings.E-ECU detects
the EGR step motor C-phase turning ON during the command
to turn OFF the EGR step motor C-phase.
3. One flash followed by three flashes.
Connector
Harness
EGR valve (step motor)
E-ECU
Movement setting at the EGR step motor error
Unavailable
Available
Error Mode
[Run As Is]:
After detecting the error, the system lets
the engine continue to run without any
restrictions.
[Run Under Restrictions]:
The engine continues to run under
restrictions.
Run restricted?
No.
Yes: The system restricts the High idle
speed or engine power.
Recovery
Conditions
No.
No.
Remarks
TNV_DI_SM_A4-Troubleshooting.book 92 ページ ２００７年１１月１５日 木曜日 午後５時２７分
