Throttle Position Sensor: Testing and Inspection

Fig. 73 Throttle position sensor terminal identification:

7M-GE & 7M-GTE Engines

1. Disconnect throttle position sensor wire connector.
2. Using suitable ohmmeter and feeler gauge inserted between throttle lever and stop screw, take the following resistance measurements:
a. With throttle closed, measure between terminals VTA and E2, Fig. 73. Resistance should be 0.3---6.3 kilo ohms.
b. With throttle lever and stop clearance of 0.0157 inch (.40 mm) on 7M-GE engines or 0.0197 inch (.50 mm) on 7M-GTE engines, measure between IDL and E2. Resistance should be less than 2.3 kilo ohms.
c. With throttle lever and stop clearance of 0.0295 inch (.75 mm) on 7M-GE engines or 0.0354 inch (.90 mm) on 7M-GTE engines, measure between IDL and E2. Resistance should be infinity.
d. With throttle valve fully opened, measure between VTA and E2. Resistance should be 3.5---10.3 kilo ohms.
e. With throttle valve in any position, measure between Vcc and E2. Resistance should be 4.25---8.25 kilo ohms.
3. If switch fails to operate as specified, adjust switch as follows:
a. Loosen switch attaching screws, then insert a 0.0228 inch (.58 mm) feeler gauge on 7M-GE engines or 0.0276 inch (.70 mm) feeler gauge on 7M-GTE engines, between throttle lever and stop screw.
b. Connect ohmmeter between IDL and E2 terminals.
c. Rotate switch clockwise until ohmmeter deflects.
d. Tighten attaching screws.
e. With throttle lever and stop clearance of 0.0157 inch (.40 mm) on 7M-GE engines or 0.0197 inch (.50 mm) on 7M-GTE engines, measure between IDL and E2. Continuity should exist.
f. With throttle lever and stop clearance of 0.0295 inch (.0295 mm) on 7M-GE engines or 0.0354 inch (.90 mm) on 7M-GTE engines, measure between IDL and E2. Continuity should not exist.
4. If switch fails to perform as indicated, switch is defective.