1986 TOYOTA CAMRY V20 air condition

Check that there is voltage between ECU terminal +B (+Bl)
and body ground. (IG SW ON) There is no voltage between ECU terminals ISC 1 ± ISC4
and E1 . (IG SW ON)
Check wiring between ECU terminal E1 and body ground.
Check wiring between ECU and EFI main
relay. Check ISC valve.
(See page FI±118)Refer to No. 1.
(See page FI±52)
Try another ECU. ..Replace ISC
valve.
Repair or replace.Repair or replace.STD voltage
No voltage
IG SW ON
Terminals ConditionTrouble
BADBAD
BAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±63

Check that there is voltage between ECU terminal W and body
ground. There is no voltage between ECU terminals W and E1.
(Idling)
Check wiring between ECU terminal E 1 and body
ground. '
Check GAUGE fuse 7.5A and ºCHECKº
engine warning light. No trouble (ºCHECKº engine warning light off)
and engine running
Check wiring between ECU terminal
W and fuse.Fuse blows again
Repair or replace.Repair or replace.
Repair or replace.
Try another ECU.STD voltage
No voltage Terminals ConditionTrouble
NO
BAD
BAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±64

Check that there is voltage between ECU terminal A/C and body
ground. There is no voltage between ECU terminals A/C and El.
(Air conditioning ON)
Check wiring between ECU terminal E 1 and body
ground.
Check that there is voltage between
amplifier terminal and body ground.
Check wiring between amplifier and
ECU or compressor.Check wiring
between ECU
terminal A/C and
amplifier. Check compressor running.Air conditioning ON
Repair or replace.Repair or replace. Try another ECU.Repair or replace.
Repair or replace.STD voltage
No voltage
IG SW ON Terminals
Condition Trouble
BAD
BAD
BADBAD
BAD No.
± EFI SYSTEMTroubleshooting with Volt OhmmeterFI±65

(b) Using SST, connect terminals TE1 and E1 of the check
connector.
SST 09843±18020
(c) After engine rpm are kept at 1,000 ± 1,300 rpm for 5
seconds, check that they return to idle speed.
If the rpm operation is not as specified, check the ISC
valve, wiring and ECU.
(d) Remove the service wire.
2. INSPECT ISC VALVE RESISTANCE
(a) Disconnect the ISC valve connector.
(b) Using an ohmmeter, measure the resistance between termi-
nal +B and other terminals (ISC1, ISC2).
Resistance: 16.0 ± 17.0


If the resistance is not as specified, replace the ISC valve.
(c) Reconnect the ISC valve connector.
ON±VEHICLE INSPECTION
1. INSPECT ISC VALVE OPERATION
(a) Initial conditions:
wEngine at normal operating temperature
wIdle speed set correctly
wTransmission in ºNº range
Idle Speed Control (ISC) Valve
(3S±FE)
± EFI SYSTEMAir Induction System (Idle Speed Control (ISC) Valve (3S±FE)FI±116

Voltage at ECU Wiring Connectors (3S±FE)
No trouble (ºCHECKº engine warning light off) and engine running
Stop light SW 4N (Brake pedal depressed) or defogger SW ONCheck connector TE1 ± E1 not connected
Check connector TE 1 ± E 1 connectedMeasuring plate fully closed
Ex. shift position P or N rangeIntake air temp. 20°C (68°F)
Coolant temp. 80°C (1 760F) Measuring plate fully open
Shift position P or N rangeThrottle valve fully closedThrottle valve fully closed
Heater blower SW ON Air conditioning ONThrottle valve open
Throttle valve open
Throttle valve open
Cranking or idlingIG SW ONSTD voltage (V) Condition
3,000 rpm
IG SW ONIG SW ON1G SW ON
IG SW ON Terminals
IG SW ON
CrankingIdling
± EFI SYSTEMElectronic Control System (Electronic Controlled Unit(ECU))
FI±133

Voltage at ECU Wiring Connectors (2VZ±FE)
No trouble (ºCHECKº engine warning light off) and engine running
Stop light SW ON (Brake pedal depressed)Check connector TE1 ± E1 not connected
Check connector TE1 ± E1 connected
Ex. shift position P or N range Measuring plate fully closed
Intake air temp. 20°C (68°F)
Coolant temp. 80°C (176°F) Measuring plate fully open
Shift position P or N range Throttle valve fully closed
Heater blower SW ON Air conditioning ON Throttle valve open Throttle valve open
Cranking or idlingSm voltage (V)
3,000 rpm IG SW ON
IG SW ON
IG SW ON
IG SW ON
IG SW ON 1G SW ON Terminals
Cranking Idling
± EFI SYSTEMElectronic Control System (Electronic Controlled Unit(ECU))
FI±134

2. INSPECT RESISTANCE OF ECU
NOTICE:
wDo not touch the ECU terminals.
wThe tester probe should be inserted into the wiring
connector from the wiring side.
Check the resistance between each terminal of the wiring
connectors.
wDisconnect the connectors from the ECU.
wMeasure the resistance at each terminal.
Resistance of ECU Wiring Connectors (3S±FE)
Measuring plate fully closed
Intake air temp. 20
°C (68°F)
Coolant temp. 80°C (176°F)
Measuring plate fully openThrottle valve fully closed
Throttle valve fully closedThrottle valve fully closed
Throttle valve fully closedThrottle valve fully open
Throttle valve fully openThrottle valve open
STD resistance ()
Throttle valve open
Condition Terminals
± EFI SYSTEMElectronic Control System (Electronic Controlled Unit
(ECU))FI±135

Resistance of ECU Wiring Connectors (2VZ±FE)
Coolant temp. 80°C (176°F)
Measuring plate fully closed
Intake air temp. 20°C (68°F)
Measuring plate fully open
Throttle valve fully closed
Throttle valve fully closed Throttle valve fully openSTD resistance (


Throttle valve open TerminalsCondition
± EFI SYSTEMElectronic Control System (Electronic Controlled Unit(ECU))
FI±136