Download DTC P0505 Idle Control System Malfunction

DI–109
DIAGNOSTICS
–
ENGINE
DI38I–04
DTC
P0505
Idle Control System Malfunction
CIRCUIT DESCRIPTION
Throttle Valve
Intake Air
Chamber
From
Air
Cleaner
Signal
The rotary solenoid type IAC valve is located on the throttle
body 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.
ECM
Valve
To Cylinder
IAC Valve
P01559
DTC No.
P0505
DTC Detecting Condition
Idle speed continues to vary greatly from the target speed
(2 trip detection logic)
2000 CELICA (RM744U)
Trouble AreaTrouble Area
S IAC valve is stuck or closed
S Open or short in IAC valve circuit
S Open or short in A/C switch circuit
S Air induction system
S ECM
DI–110
DIAGNOSTICS
–
ENGINE
WIRING DIAGRAM
B–R
Engine Room J/B
EFI
EFI
No. 1
5
3
1
2A
1
3
2C
ECM
I1
ISC Valve
2
B–R
18
1
B–W
2
E5 RSO
3
EFI Relay
7 2H
FL MAIN
W–B
12
2F
W–B
L–B
A
EB
W–B
A
EC
E3 MREL
21
A
J2
J/C
Battery
21
E5 EO1
W–B
A09123
2000 CELICA (RM744U)
DI–111
DIAGNOSTICS
–
ENGINE
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand–held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the engine warmed up or not, the air–fuel ratio lean or rich, etc.
at the time of the malfunction.
1
Check engine idle speed.
PREPARATION:
(a) Warm up engine to normal operating temperature.
(b) Switch off all accessories.
(c) Switch off alrconditioning.
(d) Shift transmission into ”N” or neutral position.
(e) Connect the OBD II scan tool or TOYOTA hand–held tester to DLC3 on the vehicle.
(f)
Using SST, connect terminals TE1 and E1 of the DLC1.
CHECK:
Check the difference of engine speed between the ones less than 5 sec. and more than 5 sec. after connecting terminals TE1 and E1 of the DLC1.
OK:
Difference of engine speed: More than 100 rpm.
OK
NG
2000 CELICA (RM744U)
Go to step 6.
DI–112
DIAGNOSTICS
2
–
ENGINE
Check voltage between terminals RSO, RSC of ECM connector and body ground.
ON
E5
Connector
RSO (+)
A09086
A09100
PREPARATION:
(a) Remove the ECM cover.
(b) Disconnect the E5 connector of ECM.
(c) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals RSO of the ECM connector and body ground,
OK:
Voltage: 9 – 14 V
OK
Go to step 4.
NG
3
Check IAC valve (See page SF–40).
NG
Replace IAC valve.
OK
Check for open and short in harness and
connector between engine room J/B No.2
and IAC valve and ECM (See page IN–30).
4
Check operation of the IAC valve (See page SF–40).
NG
OK
2000 CELICA (RM744U)
Repair or replace IAC valve.
DI–113
DIAGNOSTICS
5
–
ENGINE
Check the blockage of IAC valve and the passage to bypass the throttle valve.
NG
Repair or replace IAC valve.
OK
Check and replace ECM (See page IN–30).
6
Check for A/C signal circuit (See page AC–68).
NG
OK
Check air induction system
(See page SF–1).
2000 CELICA (RM744U)
Repair or replace.