Circuit Description

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

Throttle Position Sensor (TPS) circuits provide a voltage signal relative to throttle valve position. Throttle valve angle will vary from about 8 percent at closed throttle to about 92 percent at wide open throttle. The DC motor circuit provides a voltage signal relative to throttle angle. Mass Air Flow (MAF) sensor measures amount of air which passes through it into the engine during a given time. PCM uses MAF information to monitor engine operating conditions for fuel delivery calculations. A large quantity of air entering the engine indicates an acceleration or high load situation, while a small quantity of air indicates deceleration or idle. MAF sensor produces a frequency signal which can be monitored using a scan tool. Frequency will vary within about 4-7 grams/sec. at idle to about 25-40 grams/sec. at maximum engine load. DTC P1299 sets PCM detects system is in Electric Throttle Control (ETC) Forced Engine Shutdown Mode (Fail Safe Mode).

PCM will store conditions present when DTC was set as freeze frame data in the FAILURE RECORDS data.

PCM will turn MIL off on third consecutive trip cycle during which diagnostic runs and fault is no longer recognized. A history DTC will clear after 40 consecutive trip cycles during which diagnostic runs and fault is no longer recognized. DTC can be cleared with scan tool, or by disconnecting battery voltage feed to PCM.