I read my 97 850R mileage with ELM327 and an Android phone

[gmh]

I used the BAFX Bluetooth OBD2 scan tool and a free Android app called Elm 327 Terminal. I followed the instructions in the thread by esl_97_850_T5 called "How to read 1996-1997 Volvo 850 mileage with an ELM327".
https://www.matthewsvolvosite.com/forums ... 38#p302638
It discusses how to read the mileage stored in the instrument cluster (COMBI) using an ELM327 scan tool and a terminal emulator. My odometer was not working when I bought the car in October (stopped at 118,336) so I was eager to learn the actual mileage which is 126,480.

Thanks esl_97_850_T5!

[diggler30]

I will have to do this soon since mine has been out for at least 8k now. I need to fix that thing and this will come in handy once I get the parts for it. Thank you for the update!

[burnout8488]

Oh god, you're kidding me! Guess I know what I'll be buying now.

Although this doesn't look like it's going to be very straightforward getting the mileage out.

[gmh]

Oh god, you're kidding me! Guess I know what I'll be buying now.

Although this doesn't look like it's going to be very straightforward getting the mileage out.

It's really not bad at all. You need to type in or copy and paste the 12 commands below into the terminal one at a time, tapping send after each. The ECU responds after each, usually with OK. After the B90300 command, you'll get a string something like 85 13 51 F9 03 68 31 7E. Reverse the two pairs of numbers after F9 03 (in this case 3168) and that is the mileage stored in the cluster in hex (base 16). To decode, multiply 4th digit left of decimal times 4096 (16x16x16), the 3rd times 256 (16x16), the 2nd times 16 and 1st times 1. Add them all up and multiply by 10 and that's it.
Oh yeah, in hex A=10, B=11, C=12, D=13, E=14, F=15.

>ATZ
>ATL1
>ATE1
>ATH1
>ATAL
>ATKW0
>ATTA 13
>ATIIA 51
>ATWM 82 51 13 A1
>ATSI
>ATSH 84 51 13
>B90300

[esl_97_850_T5]

1. gmh,

esl_97_850_T5 here. You're welcome for the mileage reading details.

Thank you for the info on the free, simple Android app: "Elm 327 Terminal". I didn't know there was an Android app that allowed entering any string to the ELM327. Cool.

And thank you for your detailed explanation for those that don't have a hex calculator or don't want to use jonesrh.info/kwpd3b0_interpreter.html.

Well done!

2. everyone,

2a. The instructions that gmh listed work fine to retrieve the mileage from the 1996-1997 850 instrument cluster. However, they will not work on the 1998 V70, since they involve a 00-padded B90300 request.

A more up-to-date set of instructions would refer to B903 instead of B90300 in his "It's really not bad at all..." paragraph that explained: a) how he used the "Elm 327 Terminal" Android app to send each command/request, and b) how to decode the hexadecimal into a real life mileage.

Then the following more up-to-date list of ELM327 commands / KWPD3B0 requests should be used instead, since the following list works not only for 1996-1997 850, but also for 1998 V70 (and presumably all the 1998 70-series models), and works with OBDLink SX / OBDLink MX devices with the latest firmware, as well as with ELM327 v1.4 or later clones:

>ATZ
>ATL1
>ATE1
>ATH1
>ATSP 3A
>ATAL
>ATKW0
>ATTA 13
>ATRA 13
>ATIIA 51
>ATWM 82 51 13 A1
>ATSI
>ATSH 83 51 13
>B903

where:

- "ATSP 3A", "ATSP 3", or "ATSP A3" is only required if you can't connect without it. One of those ATSP commands should be issued the very first time you use your ELM327 compatible device with your Volvo. Then, the only other time you have to use the ATSP commands is after using your ELM327 compatible device to successfully connect with a vehicle that talks via some protocol other than ISO 9141-2.
- "ATRA 13" is very, very important to couple with the "ATTA 13". This should be used now for all Volvo years/models that use the KWPD3B0 protocol.
- "ATSI" is optional. You can delete it if you want to.
- The "ATSH 83 51 13" / "B903" combo is used, instead of the longer "ATSH 84 51 13" / "B90300" combo. The shorter form is apparently required for the 1998 cars.

2b. I'm in the process of updating jonesrh.info/volvo850/ with this more capable list of commands / requests.

2c. I wouldn't be surprised if the above list could also be used by other years and/or models. For example, they might possibly be usable by:

- some 1995 850 that have the OBDII port,
- some 1996 S70 that were (according to Wikipedia) introduced in the UK in 1996,
- very early 1999 S/V/C70.

The following simple check will tell you if the B903 request works the same with your year/model as it does for my 1997 850 T5 to record the mileage divided by 10...

Take a 1st reading. Follow that by driving some multiple of 10 miles (since the B903 counter increments once every 10 miles). Preferably drive at least 31 miles. Then take a 2nd reading. Convert the two readings using:

- a) gmh's "it's really not bad at all...reverse the two pairs of red numbers...times 4096...times 256...times 16...times 1...add up...times 10" method, or
- b) by simply pasting the two lines that contain the "F9 03 xx yy" responses into kwpd3b0_interpreter's Paste Volvo...communication here box and pressing Interpret.

Subtract the two "multiplied by 10" readings. The result should be within 9 of the # of miles known to have been driven.

2d. Of course, for those in metric oriented countries, the mileage will be in kilometers, not miles.

esl_97_850_T5

[osman]

I have wanted to know how to do this for a while as I am always buying cars that have the plastic gear in the odometer broken, so true mileage is hard to figure. Thanks for the explanation.

[esl_97_850_T5]

The 3 things that this "read mileage from instrument cluster" mechanism doesn't account for on the '96-'97 850 (and similar cars) that record mileage based on the ABS-supplied speed signal are:

1. Lost miles when the ABS did *not* supply the speed signal. To my knowledge, those miles are not recorded elsewhere. If the ABS was non-functional for months or years that can account for 1000s and 10000s of miles. For the '96-'97, there is almost always some loss from that, since the ABS modules almost always fail due to the solder joint problem.

2. Replacing the instrument cluster. This is becoming more frequent as these cars put on the years. So you can't necessarily assume the instrument cluster reflects the vehicle's real miles. A CarFax can help a lot in determining if this is a problem. For example, on my car I can tell from a combination of the CarFax and my ECU 51 B904 (Miles at Last Service Light Reset) reading that I have the same instrument cluster that was in the car in 2002-12, then by analyzing the mileages recorded in the CarFax up to that 2002-12 date, I can infer that the instrument cluster was likely never replaced.

3. Illegal reprogramming of the instrument cluster mileage. I've seen someone advertising on YouTube the ability to reprogram the instrument cluster mileage. In almost all situations, that would likely be both immoral and illegal. But people do these things. Again, reviewing the progression of mileages in CarFax may be helpful in these cases to infer if the instrument cluster mileage does not reflect the car's actual mileage (or a fairly close approximation).

esl_97_850_T5