A motronic55 install might save some time making a harness, but you must always verify the harness reasonably carefully.
This involves
- measurement of all used pins
- mostly DVM ohm-mode
- sometimes voltage mode
- visual inspection
- the injector part of the harness receives much heat. Insulation might be worn. It's better to fix ASAP, than to risk engine damage.
Use this template for your measurements.
- click "Edit this document" for this page
- click "Edit this document" for your MembersPage
- copy/paste the template from this page to your memberspage
- edit on your memberspage
- add your measurements
- save your memberspage
- save from time to time, don't risk losing many hours of edits. You can also keep snapshot of unsaved changes in a local file, especially if the browser you use is abbreviated as msie.
- close this page (without saving)
Documents and files to use
- [ motronic-AAN-ECxx.xls pinout spreadsheet]
- this is the most important docs, so you know pinout and function mapping. In MegaTune you will see names like EC36pin10 while you have it wired to some motronic pin. While you do the measurements, write the measured value and the pin you used, and any notes you think appropriate
- firmware 1.1.24 from [here]
- temperature calibration tables from EasyTherm
- coolant: NTC type 1900_256 or 2063_256 is a very good starting point
- MAT: PTC type 260_425 is a good starting point
- MegaTune (1.1.12 or later)
- latest v3gui.exe also [available here], useful for firmware upgrade
- AAN starting config and tables
- note that better tuned fuel and ignition was made for 3B engine (and successfully applied to AAN as well), see MembersPage/MarcellGal/PowerAndTraction
- normally you have some preference at the time of order, like MembersPage/TeppoKalske (page bottom). Also consider that the crew who built and tested your device might have updated it!
Sensor measurements
Measure sensor resistance against AANpin30.
- ... Ohm between 44 and 30 (MAT)
- ... Ohm between 45 and 30 (CLT)
Injector and idle-air output measurements
Measure injector and idle air pins against AANpin37 (that is the flyback pin, same function as EC36pin23 in standard VEMS docs)
- inj cyl1
- inj cyl2
- inj cyl4
- inj cyl5
- inj cyl3
Grounds
Measure that grounds are strongly (max 0.1 Ohm) connected inside the VEMS ECU.
- AANpin10
- AANpin19
- AANpin24
- AANpin30 sensor ground
- AANpin48 trigger ground
You can measure that most are connected in the harness, but at least AANpin30 (sensor ground) and AANpin... trigger ground are likely not connected.
Trigger
Measure trigger resistance against AANpin48.
- ... Ohm between 49 and 48 (135 cranktooth-VR primary trigger)
- ... Ohm between 47 and 48 (crankhome-VR secondary trigger)
HALL signal
- ... V between ... and 30 (this needs ECU plugged in and ignition on)
- changes between 0 and 4..5V as the engine rotates
This step assumes you successfully made all the above steps.
WBO2 on SSC5 male standard - applies to audi AAN and 3B (also to BMW):
- pin1 nernst,WBO2 pin 1
- pin2 WBO2 pin 3 (use a 5A fuse from +12V supply wire)
- pin3 heater(-),WBO2 pin 4
- pin4 pump(-),WBO2 pin 5
- pin5 pump(+),WBO2 pin 6
WBO2 on SSC4 male standard - applies to audi AAN and 3B (also to BMW), but the SSC5 is used by default, unless SSC4 requested:
- pin1 nernst,WBO2 pin 1
- pin2 heater(-),WBO2 pin 4
- pin3 pump(-),WBO2 pin 5
- pin4 pump(+),WBO2 pin 6
- Remember that WBO2 pin 3 must get heater+ from a 5A fuse from +12V supply wire ! The WBO2 heater+ does not come from the ECU (only the WBO2 heater-)