Service Throttle Soon Indicator Lamp

Vehicles equipped with diesel engines have an electronic throttle control system. Throttle cables are no longer used with these engines. An electronic throttle pedal assembly sends signals to the Powertrain Control Module (PCM). The PCM collects the throttle position signal, compares it with information such as road speed and transmission range, and signals a solenoid on the injector pump assembly. In this manner, precise control is kept over the entire diesel throttle system.

The "Service Throttle Soon" lamp is located in the lower right corner of the instrument cluster for vehicles equipped with diesel engines. It turns on when the ignition switch is in "RUN" and the engine is off. The lamp should turn off 1 to 5 seconds after the engine starts. If the lamp stays on or turns on while driving, service to the electronic throttle system may be required.