Speedometer Fluctuation (Replace Input/Output Speed Sensor Assembly)

Some customers may comment on a fluctuating speedometer. This fluctuation may occur at highway speeds and higher engine speeds in which the vehicle exhibits a hesitation condition. The fluctuation may also occur when the vehicle is not moving and the transaxle is in Park or Neutral, or during a vehicle launch from a stopped position.

A conductive foam emulsion may accumulate on the control valve body cover and then drips onto the module leadframe located on the control solenoid valve assembly. This emulsion coating may short the electrical circuitry of the input and output speed sensor signals resulting in an erratic speedometer.

Replace the old input and output speed sensor assembly with a newer design. This newer design incorporates the use of an integrated bi-directional zener diode that protects the speed sensor circuitry from foam-induced voltage spikes or irregularities.

1. Remove the 17 bolts from the control valve body cover.
2. Remove the control valve body cover.
3. Remove the control valve body cover gasket. Discard the gasket.



4. Clean the underside of the valve body cover of any white foam or gel-like substance.
5. Locate the electrical connector for the input and output speed sensor assembly.



6. Slide the grey locking clip in order to unlock the connector from the control valve body assembly.
7. Press the connector tab and remove the connector from the control valve body assembly.



8. Remove the bolt and manual shaft detent assembly from the control valve body assembly.




Important: It may be necessary to move the detent lever in order to gain access and remove the bolt securing the output speed sensor to the transaxle case assembly.

9. Remove the 2 bolts and the input and output speed sensor assembly from the transaxle case assembly. Discard the old speed sensor assembly.

Important: The part number for the NEW input and output speed sensor assembly is molded on both the input and output speed sensors.

10. Install the NEW input and output speed sensor assembly, P/N 24229640, and the 2 bolts on the transaxle case assembly.

Tighten
Tighten the bolts to 11N·m (8 ft-lbs).

11. Connect the input and output speed sensor connector to the control solenoid valve assembly.



12. Slide the grey locking clip in order to lock the connector in place.



13. Install the manual shaft detent assembly and bolt on the control valve body assembly.

Tighten
Tighten the bolt to 11N·m (8 ft-lbs).




14. Install a NEW control valve body cover gasket, P/N 24220201, on the transaxle case assembly.



15. Install the control valve body cover and 17 bolts on the transaxle case assembly.

Tighten
Bolts to 11 N·m(8 ft-lbs) in the sequence shown.

16. Check the transmission fluid. Refer to Transmission Fluid Checking Procedure in the appropriate Service Manual.
17. Test drive the vehicle. Drive the vehicle for 15-20 miles (24-32 km) at highway speeds in order to achieve normal operating temperatures and ensure adequate transmission fluid circulation. Verify that the speedometer fluctuation concern has been repaired.

To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System for K6310 (Sensor, Transaxle Speed - Replace).