Supply voltage B+ to most control modules -sporadic-power supply too small

[EddyK]

I am trying to get my 2008 audi a4 quattro sline 2.0l to run. I installed a new battery but still get the same codes. I ran a scan today and saw something on the scan that said main ecu relay for components was not working properly. Can anyone tell me where I might find this relay? I did have the ecu lid off and there are 3 relays underneath the ecu, 2 gray ones and a smaller black one. Any help will appreciated.

[Jay-Bee]

You were in the right area, the relays are under the ECU, check if there's any water or corrosion happening in there. The 614 is superceded by 644, most VW/Audi dealers will have them on hand. I even keep Bosch ones in stock at my NAPA store.

[EddyK]

Thanks JB for your response. One question though. I believe that the smaller black one to the left is marked 245 (or something like that). Is that one the main ECU relay? The other 2 on the right are just plain looking grey relays. Should they be numbered 644? Sorry...two questions!

[Gowking]

The smaller black one should be the fuel pump relay. When in doubt just do a part number search and you will find a description in the results.

[EddyK]

Thanks Gowking.