Engine Controls - Adjustments: A/T

Remove air cleaner, unplug Throttle Position Sensor (TPS) connector and loosen TPS screws. Insert .024" (.61 mm) feeler gauge between throttle lever and stop screw. Connect DVOM between terminals "A" and "B" of switch. See Fig 1 . Turn TPS fully counterclockwise then slowly turn clockwise until DVOM reads NO continuity. Hold and tighten switch screws to 18 INCH lbs. (2 N.m).
Using DVOM, continue check procedures for continuity with selected thickness gauges between throttle lever and stop screw. See THROTTLE POSITION SENSOR (TPS) RESISTANCE table.
If resistance value is incorrect at idle position only, adjust TPS angle and repeat test procedures. If TPS cannot be adjusted to obtain the correct values, replace TPS.

Fig 1: Identifying Throttle Position Sensor (TPS) Terminals (A/T)

Courtesy of GENERAL MOTORS CORP.

THROTTLE POSITION SENSOR (TPS) RESISTANCE (A/T ONLY)

Application Condition

Resistance (Ohms)

Between Terminals A-B ⁽¹⁾

Continuity

Between Terminals A-B ⁽²⁾

No Continuity

Between Terminals A-B ⁽³⁾

Continuity

Between Terminals A-D ⁽³⁾

4370-8130

Between Terminals A-C ⁽³⁾

240-1140

Between Terminals A-C ⁽⁴⁾

3170-6600

⁽¹⁾	With .012" (.30 mm) feeler gauge installed between stop screw and lever.

⁽²⁾	With .035" (.89 mm) feeler gauge installed between stop screw and lever.

⁽³⁾	Throttle valve at idle position.

⁽⁴⁾	Throttle valve at fully open position.

Fig 2: Calculating Intake Selective Shim Thickness for Setting Valve Clearance

Courtesy of GENERAL MOTORS CORP.

Fig 3: Calculating Exhaust Selective Shim Thickness for Setting Valve Clearance

Courtesy of GENERAL MOTORS CORP.