The trigger hardware is not particularly complex, but there are some options and things that shouldn't be missed

It is best to order with desired options (assembled controller, or with bare v3 use order comments). If you need to modify trigger hardware, also see GenBoard/VerThree/Schematic

The trigger signals are sensitive. Especially the VR signal with low pulsecount and/or at low-RPM (cranking). VR is not really sensitive from noise via capacitive coupling (although long wires that drive ignition coils arranged parallel might inject noise) but rather to noise injected through ground loop (switched power-currents that partially sneak through GND instead of GND5) if not installed properly.

The following precautions highly recommended:

Motronic55 / Audi AAN / [v3.9AAN mainboard] (primary trigger=VR; secondary trigger=auditrigger; or nonstandard/custom: HALL/HALL)

v3.6 (or newer)

Some nice pics on MembersPage/Larsa/VEMSpictures

Primary trigger is same as v3.3 - see v3.3 primary trigger=...


Secondary trigger setup is also similar to v3.3 but more versatile, allowing

Primary trigger


The image shows the config solder blobs.

v3.1 (trigg1) primary trigger=HALL

For Hall setup:

v3.1 (trigg1) primary trigger=VR

v3.2 / v3.3 (trig1) primary trigger=VR - most parts are soldered. Still check at least the SJ6 and R30.

THIS IS THE MOST COMMON SETUP - therefore it is described with picture on the trigger main page: GenBoard/Manual/InputTrigger

The 3x2 pinheader is between the EC36 and the LM1815, but

Make sure you view the board in a good orientation, so econoseal points down and "Top" or "Bottom" text is readable.

v3.2 (trig1) primary trigger=HALL

v3.3 (trig1) primary trigger=HALL

[ Converting from VR to HALL (Swedish)]

v3.2 (trig2) secondary trigger=HALL

[Picture of 2x3 header, SJ6, SJ2 on Genboard v3.2] R56 and C30 are right after SJ2 (LM1815 pin3).


There are 2 schools, one says to short SJ5 (this should work well, with no difference for a good signal). The other likes a bit extra filtering and says:

NOT short SJ5

v3.2 Primary and Secondary setup for Hall - similar instructions as above

Notes - apply both for primary an secondary trigger

Primary trigger related:

Secondary trigger related:

v3.0 .. v3.1 secondary trigger (Trigg2) VR setup (with LM1815)

U12, R58, R59, R89, R90, R91, C32, C33, C34, C40, D24, D27, SJ7 & SJ10 (shorted)

v3.2 secondary trigger (Trigg2) VR setup (with LM1815)


v3.3 secondary trigger=VR hardware setup (traditionally the AudiTrigger? setup was used for this, with masking cam-HALL unconnected)




EC36pin13 is set up for "masking HALL" (nothing to do), but beware, that this setup (with the SJ7 blob shorted) does NOT work for HALL only secondary_trigger ! :

  • OK: EC18pin12=VR, EC36pin13=masking cam HALL (for audi's 3-signal system)
  • OK: EC18pin12=VR (EC36pin13 not connected) not for audi, but for a 1-tooth VR-type cam signal (like in Fiat Stilo)

v3.3 Secondary trigger (Trigg2) Hall setup:

Special setup: VR, when input does not go below 0V - very rare!!!

You only need a series capacitance (eg. 10uF, 1210 package, 25V or 35V) when the signal otherwise does not go below 0 Volt. The capacitor allows a voltage difference, but still forward the signal.

Useful, for example when stealing the 0.65V based VR signal of an alien ECM (as on MembersPage/Gabor). SJ1 must not be shorted in this case.

The rest of the VR setup is as usual, see in the relevant section (make sure R30 pullup resistor is not soldered!)

See also