Circuit Description

WARNING: This page is about a different variant/trim than selected.

Crankshaft position sensor and camshaft position sensor are used to detect misfire. VCM monitors crankshaft speed and detects deceleration or acceleration of crankshaft that are not associated with normal engine speed. Crankshaft position sensor information is compared to engine speed and engine load to determine if a misfire occurred.

If a misfire is present, crankshaft position is compared to camshaft position sensor signal to determine which cylinder misfired. Information will be stored in separate accumulators for each cylinder. VCM evaluates number of misfires in each accumulator. A random misfire is determined if accumulators are somewhat even or if 3 or more cylinders are misfiring.

VCM also utilizes input from front wheel speed sensor to determine if a rough road condition exists which could cause crankshaft acceleration and deceleration. Diagnostic will not run if a rough road condition exists.

DTC will set when the following conditions are present:

No TP sensor DTCs are set.
No MAF DTCs are set.
No IC control DTCs are set.
No VSS DTCs are set.
No crankshaft position sensor DTCs are set.
Rough road condition is not detected.
ECT is 19-54°F (-7° to 129°C).
Engine speed is 300-4900 RPM.
System voltage is 9-16 volts.
Positive throttle position change is less than 4.9 percent for 100 milliseconds.
Negative throttle position change is less than 2.9 percent for 100 milliseconds.
Misfire is detected.