Circuit Description

Knock Sensor (KS) is used to detect engine detonation (knock). If excessive knock is present, VCM will retard timing until knock goes away. When KS module in VCM determines that an abnormally high knock level exist, VCM will set DTC. Conditions for setting DTC are:

• Timing is retarded no more than zero degrees.
• System voltage between 10-17.1 volts.
• ECT greater than 140°F (60°C).
• Engine running at least 2 minutes.
• Engine speed is 500-900 RPM.
• Knock sensor noise less than 3 counts.