Throttle Position Sensor: Adjustments

On Board Diagnostic Flow Chart (Part 1 of 2):

On Board Diagnostic Flow Chart (Part 2 of 2):

NOTE: This adjustment should be performed only when the TPS or throttle body has been replaced or when required to do so by diagnostic procedures. Engine should be at normal operating procedure before making this adjustment.

1. Enter diagnostics and select PCM override ES03 (ISC Motor).

2. Press the "COOLER" button on the Electronic Climate Control (ECC) to retract the ISC motor.

3. With the ISC fully retracted, the plunger should not be touching the throttle lever. If contact is noted, adjust the ISC plunger (turn in) with pliers so that it is not touching the throttle lever. The throttle lever must be resting on the minimum air screw. Make sure that the throttle is not being bound by the throttle, cruise, or TV cables.

4. Select PCM data ED01 (TPS) while still in PCM override ES03. Note the throttle position (in degrees) displayed on PCM parameter ED01.

^ -0.5° to +0.5° GOTO Step 6.
^ -10.0° to -0.6° OR +0.6° to +90.0° GOTO Step 5.

5. Using a torx driver T-25, loosen the TPS screws just enough to permit the sensor to be rotated. Open the throttle and allow the throttle lever to snap shut against the minimum air screw. Adjust the TPS so the parameter display is 0°. Tighten the TPS mounting screws with the sensor in the adjusted position. Recheck the parameter to be sure the TPS parameter is -0.5° to +0.5°.

6. Reconnect the ISC harness.

7. If the TPS was adjusted:
^ Exit diagnostics. Allow 20 seconds for the ISC motor to close to a pre-start level.
^ Turn the ignition "OFF" for a minimum of 10 seconds to allow the PCM to complete a "TPS Learning" procedure.

8. Start the engine and check for proper ISC motor operation.