Tacoma PreRunner Extra Cab 2WD L4-2.7L (3RZ-FE) (1998)
Idle Speed/Throttle Actuator - Electronic: Component Tests and General Diagnostics
Component Inspection
INSPECTION
1. INSPECT IAC VALVE RESISTANCE
NOTICE: "Cold" and "Hot" in the following sentences express the temperature of the coils themselves. "Cold" is from -10°C (14°F) to 50°C
(122°F) and "Hot" is from 50°C (122°F) to 100°C (212°F).
Using an ohmmeter, measure the resistance between terminal +B and other terminals (RSC, RSO).
Resistance:
Cold: 17.0 - 24.5 ohms
Hot: 21.5 - 28.5 ohms
If resistance is not as specified, replace the IAC valve.
2. INSPECT IAC VALVE OPERATION
(a) Connect the positive (+) lead from the battery to terminal +B and negative (-) lead to terminal RSC and check that the valve is closed.
(b) Connect the positive (+) lead from the battery to terminal +B and negative (-) lead to terminal RSO and check that the valve is open.
On-Vehicle Inspection
ON-VEHICLE INSPECTION
INSPECT IAC VALVE OPERATION
(a) initial conditions:
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Engine at normal operating temperature
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idle speed check correctly