TP Sensor Adjustment

Disconnect negative battery cable. Unplug TP sensor connector and insert a .026" (0.65 mm) feeler gauge between throttle lever and throttle stop screw. See Fig 2 . Loosen TP sensor mounting screws. Using a DVOM, measure resistance between TP sensor terminals No. 1 and 2. See THROTTLE POSITION (TP) SENSOR RESISTANCE table.
Turn TP sensor fully counterclockwise, then clockwise slowly to locate point where DVOM reading changes from zero to infinity. Holding TP sensor at that position, tighten TP sensor mounting screws snug.
Ensure continuity does not exist between terminals No. 1 and 2 when a .031" (0.8 mm) feeler gauge is inserted between throttle lever and throttle stop screw. See Fig 1 and Fig 2 .
Ensure continuity exists between terminals No. 1 and 2 when a .020" (0.5 mm) feeler gauge is inserted between throttle lever and throttle stop screw. Tighten TP sensor mounting screws to 22.8-38.4 INCH lbs. (2.5-4.5 N.m).
If continuity is not as specified in steps 3) and 4), TP sensor zero adjustment is incorrect. Repeat adjustment sequence. If results are the same after readjusting, replace TP sensor. After final adjustment is completed, reconnect TP sensor harness connector.

Fig 1: Identifying Throttle Position (TP) Sensor Terminals

Courtesy of GENERAL MOTORS CORP.

Fig 2: Inserting Feeler Gauge

Courtesy of GENERAL MOTORS CORP.

THROTTLE POSITION (TP) SENSOR RESISTANCE ⁽¹⁾

Between Terminals No.

Ohms

1 & 4

3500-6500

1 & 3

At Idle

300-2000

At Wide Open Throttle

⁽²⁾ 2000-6500

1 & 2

With .020" (.5 mm) Clearance At Stop Screw

0-500

With .031" (.8 mm) Clearance At Stop Screw

Infinity

⁽¹⁾	Refer to illustration for terminal identification. See Fig 1 .

⁽²⁾	There should be more than 2000 ohms difference between idle and wide open throttle resistance readings.