Triggers troubleshooting

Camshaft sensor false impulses

If the CKP is producing false impulses, increase the distance between the sensor and the trigger wheel.

Audi S6 (AAN)

In the stock wiring harness, the minus of the CKP and TDC signals are connected to each other and to the ground. It is required to cut these connections and wire a signal from the sensors directly to the ECU.

Stock trigger sensor wiring

Sometimes the VR trigger sensor wires are not shielded. In this case, replace the sensor wiring with a shielded one.

Sometimes CKP shield breaks at the place where the wiring passes through the firewall. At this point, there is 5-10cm of unshielded wire. This is enough for the ECU to catch interference. In this case, replace the sensor wiring with a shielded one.

Audi trigger

A typical problem of the Audi trigger is the shift of the CKP pulse over the TDC pulse with RPM increase. In the RPM log it looks like this:

Compare oscillograms at idle and when an error occurs. The reason for the problem is visible here - with an increase in RPM, the edge of the TDC pulse shifts over the edge of the CKP pulse.

There are two options for solving this problem.

The first is to turn on the inversion of the CKP. In this case, the system will operate on another edge, and the signals become divided in time.

The second option is the physical shift of the TDC pin, shown by the dashed line. In this case, the signals are also divided in time.