TPS Check/Adjust

Connect a scan tool to ALDL connector. With ignition ON, engine stopped, and throttle in specified position, verify TPS is within specifications. See TPS BASE VOLTAGE SPECIFICATIONS table. Adjust if necessary by loosening TPS screws and twisting TPS until correct voltage is reached. See Figurefor TPS exploded view. Retighten screws and verify the TPS voltage didn't change.

TPS BASE VOLTAGE SPECIFICATIONS ⁽¹⁾

Application

Voltage

Throttle Position

Normal Range

.35 - .67

Curb Idle

Setting Range

.55 +/-.1

Curb Idle

⁽¹⁾	ECM auto-zeros the TPS voltage at idle. This means the ECM reads the TPS voltage at idle as indicating 0% throttle opening (as long as the voltage is within the specified range).