Computer Command Control (C3) System

TPS Adjustment:

The cup plug covering the TPS adjustment screw is used to provide a tamper-resistant design and retain the factory setting during vehicle operation. DO NOT REMOVE the plug unless, in diagnosis, the "System Performance Check" indicates the TPS sensor is not adjusted correctly or it is necessary to replace the air horn assembly, float bowl, TPS sensor, TPS adjustment screw. This is a critical adjustment that must be performed accurately and carefully to ensure proper vehicle performance and control of emissions. If necessary to adjust the TPS sensor, proceed as follows:

1. Using a 5/64" (.078") drill, drill a hole in the steel cup plug covering the TPS adjustment screw. Use care in drilling to prevent damage to adjustment screw head.
2. Using a small slide hammer or equivalent, remove steel plug from air horn.
3. Disconnect the TPS connector and jumper all three terminals. (Jumpers can be made up using terminals 12014836 and 12014837). Make jumpers up with #16, #18 or #20 wire approximately 6" long.
4. Connect digital voltmeter from TPS connector center terminal (B) to bottom terminal (C).
5. With ignition on, engine stopped, turn the TPS screw with flat bladed screwdriver or equivalent to obtain .26 volts at curb idle throttle position with A/C OFF and IS fully retracted.
6. After adjustment, a new cup plug must be inserted in the air horn. The cup should face outward and be flush with the air horn casting. If a plug is not available, remove screw and apply lock adhesive or equivalent to screw threads, then repeat Steps 3, 4 and 5.