2010 S80 T6 Fuel Pump Replacement Possible ECM Software Update?

incman26 · Post by **incman26** » 24 Jan 2017, 18:44

I was having issues with a cold start on my S80 and after reviewing multiple forums I was able to pinpoint it down to the fuel pump starting to go out. The part number on the original pump was 31274616. After doing some part searching and finally calling the dealer I found out that the part was discontinued and was superseded by part number 31372880. I gave my VIN to make sure it matched and the VIN search came back with the same part number. After tackling the beast of a job, with the help of my brother, I managed to get the new pump installed and the car starts on first try now. However the fuel gauge now shows a little over 3/4 of a tank when the tank is completely filled. Is there a possibility that with the installation of the superseded fuel pump also required a software update to the electronic control module (ECM) or fuel control module (FCM) ?

Mark27 · Post by **Mark27** » 26 Jan 2017, 05:14

It's possible that during the install, you may have damaged or mis-positioned the float on the pump. I alsochanged my pump and that happened to me too only my gauge would stop at half tank. I faced a choice of taking it apart again or ignoring the fact that the tank is full but only reads half. I choose to ignore it since once the tank reached half it was dead accurate from that point on.

Post by **jimmy57** » 26 Jan 2017, 06:54

No software needed. As stated above, it is almost certain to be indexed a bit off and the float is hitting something that keeps it from going fully to top. The other possibility is one of the lines inside tank is out of position. There are marks, one on sender and one on tank that should be aligned. On P3 I recall it is a bump on the tank and a small arrowhead on sender.

Almo77 · Post by **Almo77** » 28 Jun 2024, 08:29

My 2008 S80 just stopped , came home turned it of and did not want to start after 30min. I did have a fuel pressure sensor code few days prior, so I did replace that but still no start. I am thinking it's a fuel.pump, can you give me some detail on the replacement job, is there an opening from the inside of the vehicle under a rear seat? Anything helps