2073913

1.

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.

2.

Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

3.

Has a problem been found?

YES

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.

NO

▶ Go to " Signal Circuit Inspection " procedure.

1.

Check reference voltage in harness

(1)

Ignition "OFF"

(2)

Disconnect IAT sensor connector.

(3)

Ignition "ON" & Engine "OFF"

(4)

Measure voltage between terminal 5 of IAT sensor harness connector and chassis ground.

Specification : Approx. 5V

note

In case of short to battery in IATS, Voltage reading can be displayed either 5V or 12V.

5V means that IATS is short to another 5V source such as MAFS power etc, and 12V means that IATS is short to battery voltage source such as Power Supply etc.

(5)

Is the measured voltage within specifications?

YES

▶ Go to " Component Inspection " procedure.

NO

▶ Go to " Check for short to ground in harness "as below.

note

Be sure that 5V reading is caused just by Intake Air Temperature Sensor Pull-up voltage not short to another 5V source such as MAFS power.

2.

Check for short to battery in harness

(1)

Ignition "OFF"

(2)

Disconnect IAT sensor connector.

(3)

Measure resistance between terminal 5 and 2 of IAT sensor harness connector.

(4)

Measure resistance between terminal 5 and 4 of IAT sensor harness connector.

Specification : Infinite

(5)

Is the measured resistance within specifications?

YES

▶ Go to " Check for open in harness " as below.

NO

▶ Check for short to battery in harness.

▶ Repair or replace as necessary. And then, go to " Verification of Vehicle Repair" procedure.

3.

Check for open in harness

(1)

Ignition "OFF"

(2)

Disconnect IAT sensor and PCM connector.

(3)

Measure resistance between terminal 5 of IAT sensor harness connector and terminal 24 / C21-B of PCM harness connector.

Specification : Approx. below 1Ω

(4)

Is the measured resistance within specifications?

YES

▶ Go to " Ground Circuit Inspection " procedure.

NO

▶ Check open in harenss between IATS connector and PCM connector.

▶ Repair or replace as necessary and then, go to " Verification of Vehicle Repair " procedure.

1.

Check for open in harness

(1)

Ignition "OFF"

(2)

Disconnect IAT sensor connector.

(3)

Measure resistance between terminal 5 of IAT sensor harness connector and chassis ground.

Specification :Approx. below 1Ω

(4)

Is the measured resistance within specifications ?

YES

▶ Go to " Component Inspection " procedure.

NO

▶ Check for open in ground harness.

▶ Repair or replace as necessary. And then, go to " Verification of Vehicle Repair" procedure.