Ignition System: Service and Repair

Ignition System Component Overview

• For trouble free operation of the electrical components a voltage of at least 11.5 volts is necessary.

• It is possible that the control module will recognize a malfunction and store a Diagnostic Trouble Code (DTC) during some tests. After completing all checks and repairs, check the DTC memory and erase the memory, if necessary.

• If the engine only starts briefly and then shuts off again after troubleshooting, repairs or checking of the components, it may be that the immobilizer is blocking the Engine Control Module (ECM). The ECM may have to be adapted. Refer to the vehicle diagnostic tester.






1 Knock Sensor 2 Connector

• Gray

• Contacts are gold plated.

• Installed position, refer to => [ Installation Position of the Knock Sensor Connectors ].

2 Knock Sensor 1 Connector

• Green

• Contacts are gold plated.

• Installed position, refer to => [ Installation Position of the Knock Sensor Connectors ].

3 Knock Sensor 2 (G66)

• Installed position: The wire connection points 45° toward the right on the outside.

• Overview, refer to => [ Knock Sensor Overview ] Service and Repair.

4 Knock Sensor 1 (G61)

• Installed position: The wire connection points downward vertically.

• Overview, refer to => [ Knock Sensor Overview ] Service and Repair.

5 Bolt

• 20 Nm

• Tightening specification affects the function of the knock sensor.

6 Ignition Coil with Power Output Stage (N70, N127, N291, N292, N323)

• Removing and installing, refer to => [ Ignition Coil with Power Output Stage ] Service and Repair.

7 Spark Plug

• 25 Nm

• Type and electrode gap, refer to => [ Test Data and Spark Plugs ] Test Data and Spark Plugs.

• Remove and install using the spark plug removal tool (3122 B).

8 Bolt

• 10 Nm

9 Camshaft Position Sensor (G40)

• Contacts are gold plated.

10 O-ring

• Replace if damaged.

Installation Position of the Knock Sensor Connectors





1. Green for the knock sensor 1

2. Gray for the knock sensor 2