ION L4-2.2L VIN F (2004)
Vehicle Speed Sensor: All Technical Service Bulletins
Instruments - Speedometer Fluctuation
File in Section: 07 - Transmission/Transaxle
Bulletin No.: 04-07-30-001
Issue Date: January, 2004
Subject:
Speedometer Fluctuation (Replace Input/Output Speed Sensor Assembly)
Models Affected:
2002-2004 VUE
2003-2004 ION Vehicles
with VT25E (Vti) Transaxle (RPOs M75, M16)
Attention: Technician
Condition:
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.
Cause:
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.
Correction:
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.
Service Procedure:
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.