hy,i have an audi tt 1.8 t  8n0 906 018 a  180hp..i tryed to bench read it with vag com but i supplyed the ecu with +12v in pins 1 and 2 , and -12 v in pin 3 , 21, 62...(instead of viceversa..)now the car wont start..but ...i can still connect to ecu with vag com (no errors) ,it sees all sensors data , and also i can full read the flash am29f400 without any error.the flash checksums are all ok and also the flash is100% factory like...what is wrong ?why doesn't it start?


thanx !

Long shot... Disconnect your MAF-sensor and try to start the car.
Had a simlilar issue when my MAF-sensor was broken and LTFT was really close to the limit before lighting up the MIL-lamp. After having unplugged the ECU, the LTFT was reset and the fueling was (due to the broken MAF-sensor) quite off, resulting in a car that bearly started. Unplugged the MAF-sensor and it fired right up with a conclusion to replace the MAF-sensor.

If it hasn't got a short, an open cirquit and LTFT is still within allowed range, it will not set any although it actually might measure wrong.

so you zapped the ecu with backwards voltage and youre wondering why you have problems? seems pretty cut and dry.

if it is zapped why can i still connect with vcds and read all sensors?also i read the flash am29f400 and all is intact, including all checksums..??

i knew what's coming...just needed a confirmation...
it seemed weird to me that i can still connect and see all sensors and that it has no fault codes stored, although if i disconect one sensor it pops up immediately...