Secondary Ignition Monitor

Misfiring below an engine speed of 3000 rpm is detected by the misfiring detection system. Above 3000 rpm misfiring is detected by the ignition circuit monitoring (self- diagnosis) and prevents damage to catalytic converters.

The secondary circuit monitoring operates with a "shunt" (resistor in secondary ground line).

If, after successful ignition. the threshold voltage for misfiring detection is not reached, a defect code is stored, the fault lamp activated (US models only) and the corresponding row of cylinders deactivated.