Contrary to conventional wisdom here and on other Volvo sites, the mileage of the 1996 and 1997 Volvo 850 cars can be read from the COMBI (Instrument Panel computer) using an ELM327 device. It does not require a Volvo Scan Tool (VST) or other high cost scanner.
If you have an ELM327 v1.4 or higher, and if you can already use the ELM327 to communicate with the Volvo 850 to obtain the emission diagnostics DTCs via the ELM327 commands:
then you should be able to read (the raw data containing) the mileage(s) with the following commands:
>ATWM 82 51 13 A1
>ATSH 84 51 13
If you cut and paste those commands and the ELM327's responses -- most especially the B90300 and B90400 commands and their responses -- into the "Paste Volvo 850 communication here" box at: http://jonesrh.info/volvo850/kwpd3b0_interpreter.html
It will attempt to interpret the communication and display (what is thought to be) the "Vehicle Mileage" and the "Mileage at Service Light Reset".
It could be that I've misinterpreted the meaning of those 2 mileages and that they need to be added together to come up with the "Vehicle Mileage". You'll just have to try it and see.
Keep in mind that these two mileages do not include any "lost miles" that were impossible to record because the ABS module was not supplying a proper speed signal to the COMBI. It could be that some of the other B9nn data can be used to estimate those "lost miles".
[Note: I use the term ECU to generally refer to "electronic control unit", ie, all the car's computers or computer-like modules, rather than the more common usage as "engine control unit" to refer strictly to the engine's computer.]
For lots more information on how to retrieve all the COMBI's (ie, ECU 51's) B9nn data, suggestions how it might be interpreted, and ideas on how to guess the "lost miles", refer to: http://jonesrh.info/volvo850/elm327_reads_volvo_850_mileage.html
or check out all the pages and .rtf files that feed from my "Volvo 850 OBDII" portal: http://jonesrh.info/volvo850/index.html
I think you'll find stuff there that is, as of today 2013-05-25, found nowhere else on the net. It should answer a great number of your questions about how to communicate with 1996-1997 Volvo 850 non-engine ECUs.
There's enough information there -- even now, with the portal only partially complete -- so others can see how to add 96-97 Volvo 850 non-emission diagnostics capabilities to existing mass produced scan tools and/or standalone software packages that utilize either an ELM327 based device or a VAG/COM KKL like device.
If you dig into the FAQ, you'll probably find how to also -- with the ELM327 -- read and clear DTCs for the ABS (ECU 01), COMBI (ECU 51), SRS (ECU 58), AW 50/42 Transmission (ECU 6E), Power Seat Left (ECU 2E), and Power Seat Right (ECU 2F).
Eventually, I'd like to figure out how to properly clear the 3 Service Reset Interval limits in order to do a Service Light Reset, in addition to updating the B904 mileage that seems to be the Mileage at Service Light Reset.
In the near future, I'll focus on adding more interpretation capability to kwpd3b0_interpreter.html. It may occasionally be temporarily broken, since I do live testing. However, in those situations the interpreter should be working again within an hour or less.
I'll tentatively plan on checking this thread every week or so (if I have internet access). It would be nice to get some feedback on my various hypotheses of what the ECU 51 B9nn data means. The best way for me to get the feedback is for you to add easy-to-see, explanatory comments to the ELM327 logs that you submit for automatic, quick interpretation at: http://jonesrh.info/volvo850/kwpd3b0_interpreter.html
And this thread is the other obvious feedback vehicle.Questions I'd like to get answered
The following are the questions I'd like answered using crowd source data from 1996-1997 Volvo 850 (and 1998-1999 S70/C70 family) owners:
1. Does B903 reflect the Total Vehicle Miles (minus "lost miles")? Or must B903 and B904 be added together?
2. How does B90A factor in to a dealer (ie, VST) reported mileage, if any? Does it "manipulate" the mileage at all?
3. Does B90A reflect Months Vehicle Speed Signal is Missing (from the ABS)? Or is it an Hours figure like the author of Brick-Diag suggests?
4. Is B901 the Country Code? What values do you see for B901 data besides A4 hex = 164 decimal, which presumably means USA?
5. What other values are there for B905, besides 10 hex (which I'm assuming implies 16000 kilometers)?
6. Do all owners see a value in B905 which tends to equate to kilometers, even when they own a vehicle manufactured for the US and other non-metric country?
7. Do all owners see B906 (1/4 Days since Service Light Reset) and B904 (Mileage at Service Light Reset) correlating very highly with the last known Service Light Reset a) as recorded in a CarFax, if pre-owned at that time, or b) as your accurate (to the exact day +/- 1) maintenance records indicate, if you owned the vehicle at the time of the Service Light Reset?
8. Does anyone have experience with recording B903, B904, B905, B906, B907, B908, and B909 soon before and soon after the Service light begins its illuminating after at least one of its Service Reminder Interval limits have been reached? If so, that would help to establish more confidence that:
a) B903 and B904 are used to see if the B905 limit is reached,
b) B906 is used to see if the B907 limit is reached, and/or
c) B908 is used to see if the B909 limit is reached.
9. Does anyone have a B90B value other than FF hex? If so, have you ever had any ABS problems that caused the speedometer to act flaky? Another way to word this is question is: Does B90B mean "MANIPULATED=YES"? If not, what does it mean?
10. Another B90B question. This one to determine if it really is used to indicate whether the Turbo gauge exists in your dash. If you have a Turbo gauge, does your B90B value = FF hex? If you do not have a Turbo gauge, is your B90B value = 00?
11. Does everyone see 3 values in B90C that can be interpreted as temperatures that reflect the bottom tick mark, 1/3 position, and 1/2 (horizontal) position of the Temp gauge?
12. Does anyone see how any of the B9nn data can be interpreted as 5000 / 7000 RPM?
13. What does B90D mean? Is it something relating to "Speed Warning"? Have you ever had a "Speed Warning"? If so, what are your ECU 51 DTCs as shown when using the AE0100 command instead of a B90300 command? [The DTCs come after the "xx 13 51 EE 01" and before the checksum byte, ie, the last hex byte displayed. At least that's how they would appear if ATH1 was used to show the headers.]
14. For B90E, does everyone see either C3 hex = 195 or CD hex = 205? If not, what do you see?Reason I started a new thread
I've chosen to start a brand new thread relating to the 96-97 Volvo 850 mileage reading from the COMBI, since this one should be more ELM327 oriented.
There's already the good jimmy57 2011-10-25 22:45 post's instructions in thehttp://www.matthewsvolvosite.com/forums/viewtopic.php?t=43723&p=212426#p212488
"How do I retrieve the correct mileage on 1996 850" thread that details how to read the mileage using the VST.
And there's already takane2's "Playing with the OBD-ii... got the mileage?" 2010-03-24 thread relating to how to supposedly read the 96-97 850 mileage by pulsing OBDII pin 7 with a flashing LED tool. But I strongly distrust and disapprove of the "takane2, OBDII pin 7, flashing LED tool" hack, since it causes -- 100% of the time -- a brand new ECU 51 DTC 06 on my 1997 Volvo 850 T5 with Motronic 4.3. I never got takane2's method to work. It might work for Motronic 4.4, but considering that this is a 3 year old thread and very few people have successfully used takane2's method to read their 1996-1997 850 mileage from the COMBI, I'd suggest avoiding it, avoiding any possible damage it might do, and using the method of reading ECU 51 B903 and B904 mentioned here.
And, lastly, there's the "How to read your actual miles from the ECU" thread on how to read the Volvo 850 mileage on the pre-96 Volvo 850. That one's covered very thoroughly. But it's for pre-1996 cars and doesn't have anything to do with the 1996-1997 cars that this thread is focused on. So the pre-1996 cars should be off limits in this thread.
I'm not certain how applicable this 1996-1997 Volvo 850 mileage reading approach is to the later, 850-like, 1998-1999 S70/C70, etc. cars.
My view is that this thread should be very ELM327 Volvo 850 (and maybe S70/C70, etc, if they apply) focused. I see it as a place to discuss not just the COMBI's mileage, and not just the COMBI's B9nn data and A5nn data, but all the 850 ECUs communication via the Volvo 850's keyword D3B0 protocol. So it could also include discussion of reading and clearing those ECUs DTCs, and how the DTCs that appear in the keyword D3B0 protocol messages relate to those 3 digit codes that appear in the Volvo literature. I wouldn't mind if it also included examples of ELM327 OBDII emission diagnostics communication.How to read and clear DTCs for ABS, COMBI, AW 50/42, SRS, and Power Seats
At present, the best place on my site to see how to read and clear DTCs is at: http://jonesrh.info/volvo850/volvo_850_obdii_faq.rtfRequest to incorporate into other scanners and scanning software
I would love for this ELM327 info to be incorporated into Brick-Diag, since Brick-Diag seems like the most promising, seemingly affordable software with some VST-subset functionality. And I would love for the mileage reading and even the ELM327 capability to be merged into Vol-FCR. And, I would love for the mileage reading and non-emission diagnostics DTC reading and clearing to be incorporated into the (already ELM327 capable) Android Torque app.
But, if it isn't and/or if you just don't have the money to pay for them, then with the above minimal ELM327 commands (at the top of this post), an affordable ELM327 based device, and the info at the pages feeding from http://jonesrh.info/volvo850/index.html
, you should be able -- on your own -- to read the mileage, read the DTCs, and reset (at least some of) the DTCs for the 1996-1997 Volvo 850 ABS, COMBI, SRS, AW 50/42, and Power Seats. Thanks
This is my thanks to the many fine contributions at Matthews Volvo Site that have been indispensable when debugging some problems that I've had on my 1997 Volvo 850 T5.
I'm also deeply indebted to rkam for his very useful description of the Motronic 4.4 protocol in the very first post of his "Diagnose and communication" thread at ECUPROJECT.COM: http://forum.ecuproject.com/showthread.php?1664-Diagnose-and-communication
Without that description, I have doubts whether my Volvo 850 OBDII portal would exist today. That Motronic 4.4 protocol is the one I call the Volvo keyword D3B0 protocol (or sometimes refer to it as KWPD3B0 or KWP6227). Its high level command set possibilities (that rkam clearly lists) is the same basic protocol used by the 1996-1997 Volvo 850 ABS, COMBI, SRS, AW 50/42, and Power Seats.
I'm also thankful for the Brick-Diag Kombi screens posted at: http://gallery.volvo-welt.de/v/daniel2345/05.07.2009-0.0.0.32/
They were helpful in interpreting the COMBI B9nn data.
And, last but not least, I'm very thankful for the excellent ELM327 product and the very thorough ELM327 data sheet at: http://www.elmelectronics.com/DSheets/ELM327DS.pdf
It is an easy to understand manual.