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Component description for the knock sensor - GF07.04-P-6030SM

ENGINE 113.986 

ENGINE 113.987 

ENGINE 113.988 

ENGINE 113.989 

The knock sensors are located on the cylinder block in the V angle of the engine.

Task 

The knock sensors detect the vibrations at the crankcase of the respective cylinder bank.

Fig 1: Identifying Knock Sensor 1, Right And Left Knock Sensor 2 - Engine 113.986/987/988/989
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Function 

Vibrations on the crankcase are converted by the interior piezo-electric crystals on the knock sensors into electrical voltage signals. These signals are then transferred over a 2-pin screened line to the ME control unit (N3/10) for evaluation.

Knock sensor signal 

Piezo-electric effect: If a mechanical force acts on a crystal, electrical voltages are produced.

IMPORTANT

Knock sensor signals may also indicate engine damage, e.g. increased engine noise resulting from widened piston grooves.

Fig 2: Identifying Knock Sensor Signal Pattern - Engine 113.986/987/988/989
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