Ignition Timing: Adjustments

Ignition Maps And Knock Sensor Control:

Ignition timing is NOT adjustable, the ECM completely controls the ignition timing based on several input sensor signals. Once the ECM has determined the proper timing for current driving conditions, ignition timing follows a preset three dimensional map which will deliver optimum efficiency. If the ECM gets a signal from a knock sensor for instance, then the ECM will retard timing or switch to another timing map to prevent further pinging. Timing marks on front pulley are for crankshaft TDC alignment only.

The actual Timing value can be checked by the On-Board Diagnostics system and read by the VAG 1551 scan tool. Refer to On-Board Diagnostics II in Computers and Control Systems. Testing and Inspection