LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 246 (Engine Controls Self-Diagnostics - 3.1L Engine) >> Diagnostic Tests >> DTC P1381: Misfire Detected No EBTCM/Pcm Serial Data (Century & MALIBU) >> Circuit Description

Circuit Description

WARNING: This page is about a different car, the 2003 Pontiac Grand Prix, 2003 Chevrolet Malibu, and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

The Powertrain Control Module (PCM) detects engine misfire events by monitoring variations in the crankshaft rotation speed. Wheel speed changes caused by rough road conditions can cause changes in crankshaft speed. By monitoring the wheel speed sensors, the Anti-Lock Brake System (ABS) can determine if the vehicle is operating on a rough road. If the ABS is detecting a rough road condition severe enough to affect misfire detection, a rough road signal is sent to the PCM on the serial data circuit. If DTC P0300 is set and the rough road information is not available due to an ABS malfunction, DTC P1381 will set.