Circuit Description

A dash light is illuminated by the powertrain control module (PCM) if the diagnostics has detected certain errors related to the accelerator pedal position (APP) sensor. When the PCM is commanding the Service Throttle Soon lamp ON, the voltage potential of the circuit will be low (near 0 volts). When the PCM is commanding the Service Throttle Soon Lamp OFF, the voltage potential of the circuit will be high (near battery voltage). The primary function of the PCM in this circuit is to supply the ground for the Service Throttle Soon lamp.