Throttle Position Sensor: Adjustments

On-Board Diagnostics Diagram - Part 1 Of 2:

On-Board Diagnostics Diagram - Part 2 Of 2:

NOTE: This adjustment should be performed only when the Throttle Position (TP) sensor 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 PS03 (ISC Motor).

2. Press the "COOLER" button on the Climate Control Panel (CCP) to retract the Idle Speed Control (ISC) motor. This action will disengage the A/C compressor and command EGR "OFF". The CCP display will change from "50" to "00" as the ISC retracts.

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 PD01 (TP) while still in PCM override PS03. Note the throttle position (in degrees) displayed on PCM parameter PD01.

^ -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 TP 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 TP so the parameter display is 0°. Tighten the TP mounting screws with the sensor in the adjusted position. Recheck the parameter to be sure the TP parameter is -0.5° to +0.5°.

6. Reconnect the ISC harness.

7. If the TP 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 "TP Learning" procedure.

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