Circuit Description

WARNING: This page is about a different car, the 1997 GMC Pickup and 1997 Chevrolet Pickup. However, it is still accessible from the selected car via links, so may be relevant.

Crankshaft Position (CKP) sensor sends a reference signal to VCM indicating crankshaft position and RPM. Information is used to determine when to pulse ignition coil, fuel injectors and control ignition timing.

DTC will set when the following conditions are present:

Engine speed is less than 4000 RPM.
MAF sensor is at least 5 gm/s.
Crank sensor duty cycle is greater than 50 percent (or the ratio high ref/low ref is less than 1.8).
Engine speed displayed on scan tool is 2400 RPM.