99.9L/100km, ECU Reset and Battery Disconnection Success?
 

Hi guys,
After just getting a recon transmission installed, my p2 V70 T5 is running a bit weak. Just doesn't have the oomph that it used to. Also have a weird issue with the instantaneous fuel consumption on the trip computer. When running in around 1-3 gears under about 60kph, instantaneous fuel consumption ranges from 99.9L/100km and remains high. Even when I roll down hill it seems to say around 10L/100km!
When I hit cruising speed it's all fine though, and quite efficient.

Just wondering if anyone knows what's going on?

I tried to reset the ECU. I removed fuses 6 and 23 under the engine bay, disconnected the battery for 30 mins, then held the + and - together for 30 seconds, reconnected the battery, tried to start the car (wouldn't start), replaced the fuses and then turned it on again. No difference in anything.

I'm not sure if my reset procedure succeeded, just because (a) the DSTC service light remained on (I thought this code would be reset with the battery disconnection) and (b) all trip distances and radio presets remained stored (I thought these would go with sufficient battery disconnection.

Am I doing the right thing here? (or is it a pointless exercise anyway).

Thanks for any help, this car sure as heck is an adventure.

hmmm, if you didn't take the cables off right and got a spark (this goes for putting them back on) you could have fried something. Negative always first and always last.

You also did the "hard battery restart" wrong. You do not need to do anything more than clamp the two cables together for 30 minutes, and put them back on. I only do that procedure if the computer counters for something is very high and I need them to reset (IE misfire, counter 1000+)

Put the battery on a slow 2 amp charge for a few hours, everything connected normally. Try to start it with a charger on 40 Amp.

Thanks for the tip. So if I take the cables off and tie them together for 30 mins then I should get a reset? I didn't have any problems last time I did it, but I also don't think it did anything...

I just thought that if the battery was properly disconnected/drained then the codes such as DSTC service, and also the radio presets and trip computer mileage would all be reset, but when I did it they remained stored...

I have exactly the same issue. It's driven me mad for a few years now - try as I might I can't find anything resembling a solution on any of these forums. My mechanic (a Volvo specialist) can't diagnose it either.

If anyone out there has a solution - please enlighten us! :)

Cheers,

Andrew

Hi, I'm Mike from Poland.

I have the same problem, when I start from idle, computer shows instantaneous fuel consumption 99,9L/100 km.

I've changed the throttle, the software (ECU, ETM), flowmeter, both lambda. VIDA shows no errors, but the computer still shows 99,9L/100 km when starting from idle. Sometimes it shows like this for a long time (30 seconds or more), even when I don't accelerate, but rolling.

Hope that someone already solved this problem - come here and share the solution with us :)

the feature in the trip computer is miles per gallon instantaneous...er kilometer per liter in your case. Letting off the throttle will increase that number. When coasting the number goes up.

99.9
 

Hello I'm from Sweden
I have the same problem that you,that the computer shows 99,9. Did anyone solve the problem?
Regards
Henrik

Instantaneous L/100km meter reading very high 99
 

I am also having an intermittent issue with the instantaneous fuel consumption meter on the dash of my 2009 Volvo XC70 (~260,000 km) and had the whole car checked over by an experienced mechanic using the diagnositic computer. Nothing. Tried to search for a vacuum leak which wasn't the issue. I see that I'm not the only one. Has anyone had success to identify and correct this problem? Thank you!