Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
YES
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
▶ Go to "Signal Circuit Inspection" procedure.
■ Check voltage
IG "OFF" and disconnect IATS connector.
IG "ON" and ENG "OFF"
Measure voltage between signal terminal of IATS harness connector and chassis ground.
Specification : Approx. 5V
Is the measured voltage within specification ?
YES
Go to "Ground Circuit Inspection" procedure.
NO
If the voltage is 0V, go to "Check open in harness" as follows. If the voltage is more than 5.1V, go to "Check short to battery in harness" as follows.
■ Check short to battery in harness
IG "OFF" and disconnect IATS connector and PCM connector.
Measure resistance between signal terminal of IATS harness connector and power terminal of MAFS harness connector.
Measure resistance between signal terminal of IATS harness connector and signal terminal of MAFS harness connector.
Specification : Infinite
Is the measured resistance within specification?
YES
Go to "Component Inspection" procedure.
NO
Repair short to battery in harness and go to "Verification of Vehicle Repair" procedure.
■ Check open in harness
IG "OFF" and disconnect IATS connector and PCM connctor.
Measure resistance between signal terminal of IATS harness connector and IATS signal terminal of PCM harness connector.
Specification : below 1Ω
Is the measured resistance within specification?
YES
Go to "Ground Circuit Inspection" procedure.
NO
Repair open in harness and go to "Verification of Vehicle Repair" procedure.
■ Check open in harness
IG "OFF" and disconnect IATS connector and then IG "ON".
Measure voltage between signal terminal of IATS harness connector and chassis ground.(Measurement "A")
Measure voltage between signal and ground terminals of IATS harness connector.(Measurement "B")
Specification : Voltage difference between measurement "A" and "B" is below 200mV.
Is the measured voltage within specification ?
YES
▶ Go to "Component Inspection" procedure.
NO
▶ Repair contact resistance or open in harness and go to "Verification of Vehicle Repair" procedure.
