Knock sensors
â–¶ How to fix
- Check plug connection knock sensor 4 - Check lines knock sensor 4 - Check installation knock sensor 4 - Check tightening torque of knock sensor 4 - Renew knock sensor 4 - make an endoscopy of the concerned cylinders (Cyl: 7, 8)
What you'll see
No driver-visible symptom recorded.
System reaction
- Engine is in use with a security-offset of the ignition angle in order to not destroy the engine with knocking combustion - Possible exhaust degradation and hightened temperatures in the cat and turbo charger - Engine runs bad
Diagnostic depth
Detection
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Possible cause
- Knock sensor 4 unplugged or completly droped down - Line of knock sensor 4 has short circuit to ground or to Ubatt (DFC_KnDetSens4PortA/Bmin/Max must be present) - Lines A and B of knock sensor 4 have a short cut to each other