Throttle Position Sensor: Service and Repair
THROTTLE BODY REMOVAL1. Lower the level of the engines coolant to below the intake manifold, by draining a partial amount into a clean container.
Throttle Body Removal:
2. Installation procedures are the reverse of the removal procedures.
3. Refill the engine's coolant to the proper level.
THROTTLE BODY DISASSEMBLY
CAUTION:
a. Except when necessary for replacement, the ISC servo assembly should NOT be removed.
b. The ISC servo assembly is NOT serviceable, DO NOT disassemble.
c. If the throttle valve set screw needs to be removed, use an open-end wrench or a box wrench.
d. Do NOT remove the throttle valve.
e. When loosening a Phillips screw which has been tightened firmly, be sure to use a screwdriver that is an exact fit.
f. Be careful while removing the Throttle Position Sensor and the Idle Speed Control Servo screws. They have been coated with an adhesive.
Exploded View Of Throttle Body:
INSTALLATION OF THE TPS TO THE THROTTLE BODY
TPS:
1. Install the TPS on the throttle body and temporarily tighten the screws.
TPS Connector:
2. Connect an ohmmeter to terminals # 1 and # 3 of the TPS connector.
3. Verify that the resistance changes smoothly as the throttle valve is fully opened and closed slowly.
4. Connect the ohmmeter to terminal # 2 and terminal # 3 of the TPS connector.
5. Verify that the resistance changes smoothly as the throttle valve is fully opened and closed slowly.
If resistance changes smoothly, then the TPS has been installed correctly.
IDLE POSITION SWITCH CONTINUITY CHECK
ISC Servo Connector:
6. Check for continuity between terminal # 3 and the ground.
^ While the throttle valve is fully closed - continuity should exist.
^ While the throttle valve is fully opened - continuity should NOT exist.
Replace the Idle Speed Control Servo, if the results differ from above.