How to read your actual miles from the ECU

cpozzer · Post by **cpozzer** » 26 Apr 2007, 09:37

i just tried it now,with the car on or off makes no diffrence,the mileage is the same

claudio

Post by **Sperry** » 16 Jul 2007, 23:44

Wow! That was exciting!

I bought the car nine months ago; the owner claimed the odometer had stopped a couple months previously; he was a big man, the cushions are a bit crushed, etc. However, his ex-wife and daughters had been driving the car for the last couple of years. How many miles could a couple of highschool girls put on a car?

I racked up about 20K since starting my new job, and I'm happy to report ...

IT WORKS PERFECTLY ON A '94 850 TURBO

and I have 99,577 on the car. I guess I will go ahead and put a few C-notes into the suspension, to celebrate!

cw850nm · Post by **cw850nm** » 06 Oct 2007, 10:28

I just purchased a 97 850 with a broken odometer. All the successes on this thread are pre-96 (pre-OBDII). Any chance I could read my milage? Would the cluster memory in my car be readable on a pre-96?

Thanks.

Post by **MadeInJapan** » 06 Oct 2007, 10:37

I believe a well knowledgeable dealer service department can do this with their Volvo Scan Tool, but unfortunately most are not, and will look at you like you don't know what you're talking about.

Post by **renns** » 06 Oct 2007, 12:50

In a Canadian car with km/hr speedo, will the flashed sequence be km's or miles?

Roger.

Post by **Ozark Lee** » 06 Oct 2007, 15:48

In a Canadian car with km/hr speedo, will the flashed sequence be km's or miles?

It will read it in km's. You are actually interrogating the instrument panel itself so if it was set up to tally distance in km's that is what you should read.

...Lee

Seamonster · Post by **Seamonster** » 10 Mar 2009, 15:39

The ECU code procedure worked perfectly on the 95 850 Turbo wagon I just bought.

One reason the previous owner sold the car was that the odometer stopped working. She said she'd hardly driven it since then. The dead odometer reads 148,115, while the ECU code now reports 150,899. That's would be a difference of 2,784 miles -- pretty close, if not quite "hardly driven." (About 150 of those miles are mine.)

Meanwhile, the electronic trip meter reads 3,134, which leads me to speculate that it was reset when the odometer broke. If so, that would mean 350 more miles on the trip meter than the apparent distance travelled since the odometer broke. That could mean several different things: (1) the trip meter was reset before the odometer broke, coincidentally; (2) the trip meter cycles around after 1,000 miles(?) and the readout is entirely coincidental ; or (3) the electronic trip meter and analog odometer are not precisely calibrated together.

That last possibility makes me curious about how the trip meter actually works. I'm guessing that the whole trip/MPG metering is based on a quartz-locked computer chip; and that, like the computer clock on a PC that needs to have its date/time reset periodically, it will tend to drift slightly over time. If so, I wonder if that would account for the divergence noted above of 350 miles in relation to 2,784 miles. Could the trip meter's clock chip be that inaccurate? More generally, does anyone know how precisely the trip meter tracks with the analog odometer (perhaps based on your anecdotal experience)? Or, how accurate is the electronic dash clock? (If it and the trip meter are using the same clock chip).

NB: I've ordered a new odometer gear from FCP Groton and will tackle the dash disassembly when it arrives. And, while the discrepancy of a few thousand miles would not likely trouble some hypothetical future buyer, the drill & pencil trick of Ozark Lee looks too fun not to do! Here:
https://www.matthewsvolvosite.com/forums ... a&start=14

- Kraig

KRUZNBY · Post by **KRUZNBY** » 20 May 2009, 17:03

Just wanted to add that this procedure worked great on my new to me '94 850 Turbo Wagon. Before I purchased the car, the owner estimated 120K miles as the odometer died at 98K. To my surprise, the owner was pretty spot on as I read 117,122 miles off of the ECU. I'll be doing the odometer gear replacement soon. Thanks!

Post by **Ozark Lee** » 20 May 2009, 17:54

Since you are replacing the gear on a turbo be sure to remove the nut on the vacuum line connection for the boost gauge on the back of the instrument cluster before you try to pry it apart. The writeup in the database was on a N/A car and it really doesn't address that.

...Lee

Chzman · Post by **Chzman** » 21 May 2009, 15:33

Can someone post a picture of this "fly wire" so I can see what one looks like.

Also, where would I get one, or can I build one myself?

I am interested in checking my GLT and T5 to see how accurate the odo is.