Code No.P0711: A/T Fluid Temperature Sensor 1 System (Malfunction)

PROBABLE CAUSES

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 CONDITIONS

With driving at the vehicle speed of 40 km/h or more, if the fluid temperature (fluid temperature sensor 1) is not changed from the status with less than 20°C even after 10 minutes have elapsed, code No.P0711 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 GRSE at the wiring harness side.

OK:

Approx. 6.5 kΩ (at 10°C)

Approx. 3.5 kΩ (at 25°C)

Approx. 0.25 kΩ (at 110°C)

Q. Is the check result normal?

	Go to Step 4.

	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. 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 4.

	Repair the connector(s) or wiring harness.

STEP 4. 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.P0711 set?

	Replace the A/T-ECU.

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