Circuit Description

The throttle position sensor circuit provides a voltage signal relative to throttle position (blade angle). The throttle blade angle will vary from about 8 percent at closed throttle to about 92 percent at Wide Open Throttle (WOT). The DC motor circuit provides a voltage signal relative to command throttle position (blade angle). The Mass Air Flow (MAF) sensor measures the amount of air which passes through it into the engine during a given time. The Powertrain Control Module (PCM) uses the mass air flow information to monitor engine operating conditions for fuel delivery calculations. A large quantity of air entering the engine indicates an accelerator or high load situation, while a small quantity or air indicates deceleration or idle. The MAF sensor produces a frequency signal which can be monitored using a Tech 2. The frequency will vary within a range of around 4 to 7g/s at idle to around 25 to 40g/s at maximum engine load. This DTC detects if the system is in ETC Forced Engine Shutdown Mode (Fail safe Mode).