A/T - Fluid Temperature Sensor Diagnosis

Group: TRANSAXLE

Number: 95-40-009

Date: SEPTEMBER, 1995

Model: ALL 1994 AND LATER AUTOMATIC TRANSAXLES

Subject:
AUTOMATIC TRANSAXLE
FLUID TEMPERATURE SENSOR
OPERATION AND DIAGNOSIS PROCEDURES

DESCRIPTION:

Beginning with the 1994 model year the Transaxle Control Module utilizes the Automatic Transaxle Fluid Temperature Sensor to control shifting if the ATF Temperature rises above 125°C (257°).

If the ATF temperature exceeds 125°C, the transaxle may automatically down shift into 3rd or 2nd gear (increasing engine RPM) to reduce torque slip, thus reducing fluid temperature. If this occurs, a customer may note increased rpm while cruising but without an increase in vehicle speed.

When the fluid returns to 110° (230°F) or below, the transaxle operation will return to normal with no diagnostic trouble code stored.

Diagnosis:

1. Insure the Automatic Transaxle is filled to the proper level (proper. checking procedures are described in the shop manual) and that the fluid is in good condition.

Note:
Always use Hyundai Automatic Transaxle Fluid or Chrysler Mopar ATF Plus type 7176. Do not use any type of Dexron or Mercon ATF.

2. Check the external transaxle cooler (If so equipped) for debris that may block the air flow across the cooler.

3. Verify the engine coolant system is operating properly and that the engine coolant is at the proper level.

Note:
With a cold engine, remove the radiator cap and insure the radiator is full.





4. Verify ATF temperature sensor operation using the scan tool.





If a scan tool is unavailable, you may use a DVOM. Illustrated is a temperature and resistance chart.

Note:
To test the sensor on an Accent you must first remove the battery and battery tray to access the sensor. Remove the connector from the sensor which is located near the transaxle dipstick. Using a DVOM you may now check the sensor and compare the results with the chart.

Note:
Always record the customer1s radio station settings prior to disconnecting the battery.

If the ATF temperature sensor is not within specification, replace the sensor.

AUTOMATIC TRANSAXLE ATF TEMPERATURE SENSOR REPLACEMENT PROCEDURES

1. Drain the ATF and remove the transaxle oil pan.





2. Remove the clip that secures the temperature sensor to the valve body.

3. Squeeze the tabs of the connector to release it from the transaxle case and pull the connector and the sensor from the case.

4. Confirm that the replacement sensor operates within specifications using a DVOM and the chart in this bulletin.

5. Install the new sensor into the clip, then onto the valve body and torque to 3 to 4 lb ft.

6. Install the oil pan with a new gasket.

7. Fill with ATF to the proper level according to the appropriate shop manual.

Note:
Always use Hyundai Automatic Transaxle Fluid or Chrysler Mopar ATF Plus type 7176. Do not use any type of Dexron of Mercon ATF.