DTC P1530: Throttle Control System - Amplifier Adjustment: Description

WARNING: This page is about a different car, the 2002 Saturn LW300 and 2002 Saturn L300. However, it is still accessible from the selected car via links, so may be relevant.

The Throttle Actuator Control (TAC) module contains 2 throttle position sensors with a common 5-volt supply, a common ground, and 2 independent signal circuits that vary resistance according to changes in throttle plate position. The ECM measures the signal voltage from each TP sensor, which is a reduced value of the ECM 5-volt reference. The ECM reads the voltage levels from TP sensor 1, then converts the voltage level to a binary number. This binary number is limited to 0.019 volts/bit based on the range of 5 volts. At low throttle angle, the ECM needs to amplify the TP sensor No. 1 signal in order to obtain a more accurate binary number equivalent for very slight changes in throttle angle. The ECM will monitor the TP sensor No. 1 amplification output whenever a key-up closed throttle test is performed (once per key-up). DTC P1530 will set if the TP sensor No. 1 amplification output does not correlate with the TP sensor No. 1 signal voltage.