I've got a 98 a4 1.8t that I just replaced the engine on (threw a rod)and the da*n thing wont start and I cant communicate with the ecm/ecu. Checked for loose wires, blown fuses etc. and even swapped the ecm and still wont start or give any reading from the ecu. I took it to a local import repair place and they are saying it is probably another control module shorting out and messing up the whole system. In his example he said that if the abs control module shorted out it could prevent the scan tool from communicating with anything even the ecu since it's all on the same data link. This sounds kinda fishy to me, is this possible? He said it will probably take 2-4 hours to find the problem but he makes no guarantee. I told them to start with 2 hours and call me before they did anything else. Please help $75/hr is going to kill me.

Thanks

 

Did you replace the head unit?

 

No sir.

 

Doubt it is the ABS. Check the connections at the ECU.

 

I have checked them many times. Thanks for the reply tho.

 

check the starter motor, I took apart the front of my engine and popped out the transmission to replace some things. when we pieced it back together the power cable from wherever that connects to the starter motor had fallen out and my car wouldnt start. Just a suggestion from my car troubles

 

I will check the starter.

Thanks

 

Does "won't start" mean:

#1 - Turn the key - nothing happens
#2 - Turn the key - and the engine cranks but no spark
#3 - Turn the key - and the engine cranks and sputters but won't stay going.

 

It cranks but wont start. Its getting fuel to the rail but the injectors are not opening and I cant communicate with any control modules-ecu, abs etc with my scan tool. More info in my last thread https://www.audiforums.com/m_564605/tm.htm

Thanks

 

Got it fixed. Maybe this will help someone in the future. Details here https://www.audiforums.com/m_573053/.../tm.htm#573680