Code No.P0712: A/T Fluid Temperature Sensor 1 System (Short Circuit)

OPERATION

The A/T fluid temperature sensor 1 converts the A/T fluid temperature to voltage, and send the information to the A/T-ECU.
The A/T fluid temperature rises, the resistance decreases. Thus, the sensor output voltage depends on the A/T fluid temperature. As the A/T fluid temperature rises, the output voltage will decrease.

DIAGNOSIS CODE SET CONDITION

While the engine is running, when a status continues for 60 seconds with which the input voltage from fluid temperature sensor 1 is less than standard value, code No.P0712 is set.

PROBABLE CAUSES

Malfunction of the A/T fluid temperature sensor 1
Damaged harness wires and connectors
Malfunction of the A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. Measure the resistance at A/T-ECU connector.

Disconnect the connector, and measure the resistance between terminal O/TS and body earth at the wiring harness side.

OK: No continuity

Q. Is the check result normal?

	Go to Step 5.

	Go to Step 2.

STEP 2. Check the A/T fluid temperature sensor 1.

Refer to

Q. Is the check result normal?

	Go to Step 3.

	Replace the transmission wiring harness.

STEP 3. Measure the resistance at A/T-ECU connector.

Disconnect the connector, and measure the resistance between terminal O/TS and body earth at the wiring harness side.

OK: No continuity

Q. Is the check result normal?

	Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

	Go to Step 4.

STEP 4. Check for open circuit and short circuit in O/TS, GRSE line between transmission wiring harness connector and A/T-ECU connector.

Q. Is the check result normal?

	Go to Step 5.

	Repair the connector(s) or wiring harness.

STEP 5. Check whether the diagnosis code is set again.

Ignition switch: "LOCK"(OFF) → "ON"
Check again if the diagnosis code is set.

Q. Is diagnosis code No.P0712 set?

	Replace the A/T-ECU.

	Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).