Subpage of MembersPage/MarcellGal/PowerAndTraction, the implementation of PlugAndPlayMotronic on Audi 200 quattro 20V turbo

We used 6+2 style ignition output (6 power IGBT-s + 2 logiclevel ignouts) for all PNP ECUs (and econoseal ECU-s made for PNP-adapters for these 10VT/20VT enginse) so far. This way, using the 4 stepper outputs, there is a quick migration between using

2+6 might also make sense (2 lines to clamp instead of 3) if one is certain he'll use logiclevel coils/modules (the ones factory setup, or other) later as well.

The differences between

is trivial. If one can make either, he can make any other work.

However, there are a few details that is nice to have.

Tach freq-signal (AANpin40, 3Bpin6) to drive the factory cockpit tachometer gauge is simple:

  • Question on the Tacho Pull up voltage, lookig at the V3.3 schematic, shows the on board pull up component, R164, R166, R167, R168, for P259 channels, at 12v not 5v??????, Sprocket, 08-01-2008

Trip computer boost display

Vehicle-speed AAN motronic55pin50

It would be awesome to log this. With only RPM, MAP and TPS (vs time) in logs, it involves heuristics to find out the gear. With vehicle-speed data (either from this signal, or from a GPS which has elevation and climb data as well), road-dynoing becomes easier to automate.

  • Emil and Andrey suggested to capture the vehicle speed with the free input signal when PS2 not used.

in the Audi 100/200/S4 ? Likely the same in the 80/90 chassis.

Trip computer fuel-consumption display

Now AAN motronic55pin31 connected to s259pin6 (s259-2 that is GenBoard/Manual/DigitalOut/Table 0x26) via 1k*10uF RC filter.

The manual shows that a potentiometer<variable resistor> described as a fuel consumption sensor in the Fuel distribution head/flow meter measures the position of the plate, just like a TPS. It's a 3 wire sensor that connects directly to the gauge for its power, ground and signal

The gauge cluster has some adjustment for fuel consumption trim between 0 and 15% is described in the manual using some switches or a resistor on the cluster itself.

I can take measurements of the Sensor with the throttle plate closed, at idle and at WOT if they are useful. => not really useful.

Speculation and experience

MembersPage/EmilLarsson knows the bmw's do some strange calcs inside cluster, for fuel consumption: the gauge starts moving when hooking up tachometer.

MembersPage/SamiKorhonen : some guy used 0-5V signal what his old KE-jetronics MAF gave to his computer.

In fact the tach signal, and a 0..5V signal should be all that is needed. We just have to find out if the signal is rather proportional with MAF or MAP or injector-pulsewidth, or something else ;-)

CLT and MAT on an Audi AAN (20VT) engine

Measuring against motronic pin 30 (sensor GND, mislabelled in our s2central doc), our DVM can see the CLT (pin45) and MAT (pin44) sensors from the motronic55 connector. Since the sensors are grounded through ECU, using other ground pin for measurement will not see the sensors.

CLT (coolant) is measured at a few points

It is strongly recommended to use lower MAT pullup resistor value than the factory 2k7. I used 1/(1/2700 + 1/510)=429 Ohm (430 Ohm would be perfect as well. If your ECU is clamped, you can change by removing endplate only, or use an 510 Ohm pullup to 5V outside that becomes effective 429 Ohm together with the internal pullup, as the above calculation suggests). This "stronger pullup" gives appr 2x as good resolution. I uploaded my PTC MAT sensor calibration to EasyTherm/SensorTable

From 1.1.29 the firmware uses 11 bit sampling internally, so the airden and MAT reading is smoother for the steep PTC curve.

Check Engine Light (CEL)

It would be nice to figure out a way to enable the check engine light. Most inspection stations in the USA require the check engine light on OBD1 cars (like the urS4 / urS6) to come on with key on for a few seconds, then go out. How can this be accomplished? Looking at the wiring diagrams the light appears to be ground-activated by the ECU on pin 22.