Dallanar

Hey all last week i put a used 43k 2.7L T AT in my 00 a6 to replace the blown motor that was in it, i got everything hooked up, car gets fuel, spark, and cranks just won't start, also my obd2 scanner will not communicate with the ECU at all, i tried my tool, as well as cheapo ebay cable with vcds lite, only thing the vcds picks up is radio and interm modules, all lights and everything work no check engine light on display, My question is what are the chances my ECU is trashed which is causing the car not to start, seems like it is getting too much air or choking itself upon cranking. Any Suggestions are very much appreciated

Dallanar

so after hours of reading and checking and more reading today, i went out to the car pulled lower dash down to access relay panel above pedals, i checked the 40a,50a and 5a fuses in there changed the 40 out with a new one, also noticed that there was a relay partly unplugged from its location, big brown *603 relay part # 4Bo 955 531E i then rechecked all fuses in panel on drivers side dash, swapped a few fuses around just in case, and low and behold the ABS light went out, and my obdII scanner now communicates battery is low on voltage so charging now then gonna try to fire it up, so looks like my abs module/ecu module are both working im able to access every module from the pocket scanner i have. going to hook up vcds lite to it next and see if that will scan ok since that didnt work right yesterday either. Ill update you guys when i find out if it starts or not. Even though i got no response thanx for those who at least viewed the issue.

RMsALFA

Relay 603 is part of the windscreen wiper system (I think)

Dallanar

Yea i believe you are right, it may not have been that relay that did it, could have been the 4-5 fuses i changed out, but i tried changing out ecu fuses and such yesterday and no success and abs light was on still after, so i dont know if there is something in that relay that affects other areas or not.

Dallanar

Ok so i was able to crank the car a few times for around 30 secs or so per crank, enough to draw 2 codes, im getting a p0341, p0346 code the car still wont start, although im sure it is flooded by now will be pulling plugs and putting back in. i have a spare sensor so i swapped it with bank 1 sensor still drawing code, the motor i put in came in time as i checked prior to installation, it came as a whole motor and everything sounds fine while it is cranking just wont turn over, is there maybe a fuse or relay for those sensors? as i have found some bad fuses and relays already which i replaced?

Dallanar

I have been doing a lot of reading up on these 2 codes, i found a pdf that says possible reasons for the codes, either timing is off- which it isn't, sensors are bad, VVT sensors bad, crank pos. sensor bad, or ecu bad, i checked the crank/cam sprocket timing yesterday that was dead on, i have not pulled valve covers to check cam chain timing yet, but as i said the motor came as a complete unit, with 43k miles on it, has never been taken apart, and was run tested prior to sale. I have also read the car should still start with bad cam sensors but not with bad crank sensor. I need some input as i get one problem cleared i stumble to another. will be rechecking all wiring in a few minutes.

Dallanar

Vehicle: 2000 Audi AUDI A6
Part Details: Engine - 2.7L (VIN D, 5th digit,turbo) AT
Mileage: ~43K Car Fax Certified
Price $1,995.00 (*Includes FREE SHIPPING!)

• 3 Year Parts and Labor Nation Wide warranty available on most engines.
• FREE SHIPPING in the 48 states.
• All reasonable offers will be CONSIDERED.
• All miles are CARFAX verified.
• Please read all the TESTIMONIALS on our website.
• All ENGINES are started , compression tested, and cylinder leak down tested.
• ALL ENGINES checked for oil pressure and cleaned.
• Please include original request with reply!!!!!
• For more information please visit our website
• 180 day standard engine warrant

this is the engine i purchased and is in the car now, if engine was in fact started and tested as stated which i believe it was engine comes from a reputable source, the timing is on, like i said i checked the crank- cam pulley and everything lines up just didnt check under valve covers yet. what do you guys think?

69gaugeman

Do a compression test. You have two of the three variables needed to run a internal combustion engine.

Dallanar

as stated above gaugeman the engine was already compression tested prior to purchase, i disconnected the crank sensor and the p0341,p0346 codes werent there just a p0322, when i hook the sensor back up it blows the first 2 i ordered a crank sensor which will be here friday. I rechecked timing to make sure and it is dead on, pulled passenger side valve cover to check cam alignment on that side as well and when all marks are lined up cyl#3 is tdc, so timing isnt the issue, hoping this crank sensor clears it up for me, as many others on another forum have stated it is most likely the crank sensor i wanted to rule out everything else first. will keep you guys posted