1994 Geo Tracker LSi, 1.6 U, AutomaticFACTORY OEM SERVICE PROCEDURE

Throttle Position (TP) Sensor

  1. A malfunction in the throttle position sensor circuit will set diagnostic trouble Codes 21 and/or 22. For testing and adjusting procedures, see THROTTLE POSITION (TP) SENSOR in ADJUSTMENTS article in this section. Use the following procedure to diagnose TP sensor.
  2. Using ohmmeter, measure resistance or continuity of throttle position sensor between designated terminals with selected feeler gauge thickness between throttle lever and stop screw. See Fig 1 . Adjust or replace TP sensor if resistance is not within specification. See THROTTLE POSITION (TP) SENSOR RESISTANCE  table.
Fig 1: Identifying TP Sensor Terminals
G94C44166Courtesy of GENERAL MOTORS CORP.
THROTTLE POSITION (TP) SENSOR RESISTANCE

Application Ohms
TBI - Federal
Between Terminals 2 & 4 3500-6500
Between Terminals 3 & 4 (1) 0-500
Between Terminals 3 & 4 (4) Infinity
Between Terminals 4 & 5 (2) 300-2000
Between Terminals 4 & 5 (3) 2000-6500
MFI - Calif. & New York
Between Terminals 1 & 3 3500-6500
Between Terminals 1 & 2 (5) 0-500
Between Terminals 1 & 2 (6) Infinity
Between Terminals 1 & 4 (2) 300-2000
Between Terminals 1 & 4 (3) 2000-6500
(1) With .012" (.30 mm) feeler gauge installed between throttle stop screw and lever.
(2) Throttle valve at idle position.
(3) Throttle valve at fully open position.
(4) With .022" (.56 mm) feeler gauge installed between throttle stop screw and lever.
(5) With .020" (.50 mm) feeler gauge installed between throttle stop screw and lever.
(6) With .031" (.80 mm) feeler gauge installed between throttle stop screw and lever.
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