Speedometer Dead

[MrAl]

Do the abs/tracs off lights illuminate for a few seconds when you start the car? Yes/no

Have the abs/TRACS off lights been on, if so how long?

Does the "SERVICE" currently blink continously or has it at any recent time?

Hello there and nice to meet you.

I will have to test this tomorrow i don't know offhand if the abs lights illuminate for a few seconds or not because i was not looking for that (yet). I just found out the last time i drove the car back from the store, so i parked and that was it for that time. Since i know the problem is there now i can go out and test a little but it will have to be tomorrow. I will surely get back here tomorrow sometime.

I do know the abs lights are not on, i am guessing i would see that. That's unless i have to drive the car again to see it/them come on. I dont think i have tracs though on this car.

The service light came on, but i did not see it blink. It just went off when i drove to the store. I did not notice what it did on the way home because i was rather dumbfounded that the speedometer needle did not move even a tiny bit at some 35mph. I reset the trip odometer and that did not increment at all either, but now that i think about it i did not notice the regular long term odometer i'l have to check that tomorrow too.

I am going to test the car and take it for a test drive tomorrow so i will get back here.
Thanks very much for the ideas and suggestions this car as been almost a nightmare all of a sudden, after some 6 years of having some rather regular easy to understand problems.

I guess you sell and repair some of these parts that go into this kind of car? That's nice to know and i will use your service for sure if it is one of those things you can repair.

Thanks again and i will get back here tomorrow, probably afternoon.

Take care for now,
AL

[scot850]

The ABS and if the car has TRACs have lights in the warning lights along the bottom of the speedo console where the check engine light is. Do you still have an owner's handbook? If not here is a link. You want page 19 and look at all the warning lights you should have:

https://volvo.custhelp.com/app/manuals/ ... /om_id/952

There is always a possibility someone has removed the light bulbs? Do the TRACS (not all cars have this) and ABS lights come on when you turn the ignition key to Pos II?

Neil.

[MrAl]

The ABS and if the car has TRACs have lights in the warning lights along the bottom of the speedo console where the check engine light is. Do you still have an owner's handbook? If not here is a link. You want page 19 and look at all the warning lights you should have:

https://volvo.custhelp.com/app/manuals/ ... /om_id/952

There is always a possibility someone has removed the light bulbs? Do the TRACS (not all cars have this) and ABS lights come on when you turn the ignition key to Pos II?

Neil.

Hi Neil,

Which position is position II is that before the car cranks over or after that?
I never see any lights come on that look unusual to me, but I'll have to double check that because I did not notice this time.


I did get to check the OBDII for the speedometer, and it reads zero constantly. I believe it is a live update because the other things like Throttle are live and change with the pressure on the gas petal. I drove about 3 miles total round trip and the speedometer never changed it stay at "0".

I do actually have Tracs i didn't think i did but there is a button for that near the cluster.

[MrAl]

.. or if have PC and ELM327 with full V1.4b compatible device then https://jonesrh.info/volvo850/volvo850diag.html Volvo850diag is very good call.

If have Android device and ELM327 with full V1.4b compatible device then one way is use an App "850 OBD-II" to read directly ABS module data. *Disclaimer i am guilty of this then.

This, right here, is the post to follow and use for the diagnostics/code reading.

Pick up a BlueTooth ELM327 device and either use the app (if you have an Android phone) or a PC.

This will get you the DTCs and a direction. If you want to fire the parts cannon at it, then start with the driver side front wheel sensor, but I would recommend getting codes first.

The "850 OBD-II" app is great and I highly recommend it. You can even do a "Gauge Test" and it will get codes for pretty much any system that OBD-II is connected to in the car. (It even picks up DTCs for the power driver seat in my wife's car...)

(You can also change the "Service" light interval, which you cannot do with most scanners)

Hello again,

I am looking at some new code readers and i see there are cheap ones and more expensive ones, the ELM327 thing. How much do you think i should spend on a BT ELM327 scanner?
The scanner i have now does not show information like ABS at all.

Oh I did get to check the OBDII for the speedometer, and it reads zero constantly. I believe it is a live update because the other things like Throttle are live and change with the pressure on the gas petal. I drove about 3 miles total round trip and the OBDII speedometer never changed it stay at "0".
What do you think that means?

[scot850]

Pos I is the first click when accessories work. Pos II is when all the dash warning lights light up. After that it is when you turn the last bit to get the engine turn over. If you look at the ring around the ignition key it should be marked.

Neil.

[xanthefin]

.. or if have PC and ELM327 with full V1.4b compatible device then https://jonesrh.info/volvo850/volvo850diag.html Volvo850diag is very good call.

If have Android device and ELM327 with full V1.4b compatible device then one way is use an App "850 OBD-II" to read directly ABS module data. *Disclaimer i am guilty of this then.

This, right here, is the post to follow and use for the diagnostics/code reading.

Pick up a BlueTooth ELM327 device and either use the app (if you have an Android phone) or a PC.

This will get you the DTCs and a direction. If you want to fire the parts cannon at it, then start with the driver side front wheel sensor, but I would recommend getting codes first.

The "850 OBD-II" app is great and I highly recommend it. You can even do a "Gauge Test" and it will get codes for pretty much any system that OBD-II is connected to in the car. (It even picks up DTCs for the power driver seat in my wife's car...)

(You can also change the "Service" light interval, which you cannot do with most scanners)

Hello again,

I am looking at some new code readers and i see there are cheap ones and more expensive ones, the ELM327 thing. How much do you think i should spend on a BT ELM327 scanner?
The scanner i have now does not show information like ABS at all.

Oh I did get to check the OBDII for the speedometer, and it reads zero constantly. I believe it is a live update because the other things like Throttle are live and change with the pressure on the gas petal. I drove about 3 miles total round trip and the OBDII speedometer never changed it stay at "0".
What do you think that means?

I personally wouldn't spend much. If local there is BAFX and VeePeak could get work mostly if not bad clone of them then and original OBDLink products but they get more expensive easily. If you looking from China look it has PIC chip as mostly they have good enough firmware to work.

Mostly you reading now from Motronic ECM the speed signal as it has OBDII standard PID for speedo.

Some module should be screaming though for missing speed signal honestly but i don't remember now which one could and do they set Pxxx code over it anywhere or set MIL light on (if bulb is not burned too).

I would think you have somewhere broken signal but.. others have already given very good tips look out that as can without reader like lights on dashboard when turning ignition on etc..

[MrAl]

Pos I is the first click when accessories work. Pos II is when all the dash warning lights light up. After that it is when you turn the last bit to get the engine turn over. If you look at the ring around the ignition key it should be marked.

Neil.

Oh ok, thanks.

So what is supposed to happen in Pos II, and what does it tell us if it does not happen?
Like say a light is supposed to come on and it doesn't, or it isn't supposed to come on and it does.

[scot850]

If a light does not come on, then someone may have removed the bulb to hide a fault, the bulb has failed ( not common). The only other reason is there is a wiring issue, but I believe (no certain) the light should come on for both Tracs and ABS. If it does not come on there is an issue. They come on in PosII like a check sum, and then should go out after starting if all is good.

Neil.

[MrAl]

If a light does not come on, then someone may have removed the bulb to hide a fault, the bulb has failed ( not common). The only other reason is there is a wiring issue, but I believe (no certain) the light should come on for both Tracs and ABS. If it does not come on there is an issue. They come on in PosII like a check sum, and then should go out after starting if all is good.

Neil.

Hi Neil,

Oh ok I'll check that out soon. Thanks.

[MrAl]

If a light does not come on, then someone may have removed the bulb to hide a fault, the bulb has failed ( not common). The only other reason is there is a wiring issue, but I believe (no certain) the light should come on for both Tracs and ABS. If it does not come on there is an issue. They come on in PosII like a check sum, and then should go out after starting if all is good.

Neil.

Hi,

I did not see any Tracs light, but i did see a light labeled "Brake". Could the Brake be the ABS light?
Where is the Tracs light on the dash supposed to be?