Idle Control System Malfunction - Toyota T100 1996 Service Manual

DI−94
DTC P0505
CIRCUIT DESCRIPTION
Throttle Valve
From
Air
Cleaner
Signal
ECM
Valve
DTC No.
Idle speed continues to vary greatly from target speed
P0505
(2 trip detection logic)
WIRING DIAGRAM
From Battery
From
IG Switch
3 1A
J/B
No.1
17
1C
4
EA1
B−Y
1996 TOYOTA T100 (RM449U)
DIAGNOSTICS

Idle Control System Malfunction

Intake Air
Chamber
To Cylinder
IAC Valve
P01559
DTC Detecting Condition
B−W
2
2
EFI
2
R/B No.2
− ENGINE (3RZ−FE)
The rotary solenoid type IAC valve is located in front of the in-
take air chamber and intake air bypassing the throttle valve is
directed to the IAC valve through a passage.
In this way the intake air volume bypassing the throttle valve is
regulated, controlling the engine speed.
The ECM operates only the IAC valve to perform idle−up and
provide feedback for the target idling speed.
S IAC valve is stuck or closed
S Open or short in IAC valve circuit
S Air intake (hose loose)
9
9
2
EFI Relay
W−R
2
5 3
W−B
2
1 2
Trouble Area
IAC
Valve
V−Y
3
W−R
2
V−R
IE1
1
EA1
EA
DI0TZ−03
ECM
9 6
RSC
E7 E7
E01
10 7
RSO
E7 E7
(M/T)(A/T)
E01
P19957