ABS Computer - speedometer question

[mikolasr]

About six months ago my left rear wheel speed sensor went bad and the speedometer worked intermittently. I continued to drive without repairing it until it stopped working completely (I have GPS speedometer too) and eventually the ABS light came on and that computer is messed up. I know this all now because my dealership diagnosed the codes. Today I replaced the left rear wheel speed sensor and expected the speedometer to start working. No luck. Will it not work while the ABS computer is still fouled up? I plan on sending it for a rebuild but I thought the speedometer would work anyhow. Anyone know?

[thematrixz]

In my case, the ABS controller went bad but the speedometer still worked.

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1999 540ITA Sports, Dinan CAI & software. M5 rear swaybar. Debadged for you pleasure.
Phatbox now installed + in-dash CD
M-Technik Aerodynamic

1999 528IT, no mods...yet

[Jim Cash]

It depends on what is wrong with the ABS unit - but it is the source of the information that is transmitted to the instrument cluster which is then converted to a speed indication.

Cheers
Jim Cash

[rajaieq]

Just to embellish on Jim's explanation. I believe all 4 speed sensors are connected to the ABS controller. The ABS takes the readings and then passes the data over communication bus(s) to other controllers which need the info (speedo, CC, tranny control).
According to the type of ABS controller failure, sometimes the data is passed on and sometimes it is not.

If my information is correct, then your cruise control should also not be working and your auto tranny should be having shifting problems.
Rajaie
528i 5sp 06/00

[frankya]

>>"If my information is correct, then your cruise control should also not be working and your auto tranny should be having shifting problems."


Um, not precisely. One - search on "ABS controller" and you'll find this over and over.....Depending on EXACTLY which part of ABS ECU fails, you may or may NOT have either cruise, speedo, trans issues.

Speed is left rear sensor and associated ABS circuitry, cruise is rr. Unless both are effected( or both sensors bad), one will work, the other will not. Trans is rumored to be a front sensor and circuitry, BTW.

fy

[slwhite]

My ABS light is on although the person I just purchased from says the sensor was replaced, and my speedometer isn't reliable. So, is this at all a DIY fix? Any estimates on how much to replace ABS control module?

[frankya]

As has been discussed about 6 times in the last 5 weeks:
About $610.00 from Roadfly featured vendor Crevier BMW plus 1 hour labor time to code module by dealer or independent with GT-1 or MODIC.

[rajaieq]

Give me an example post of someone with the following condition.
A failing ABS controller that does not pass the info from a good sensor but passes on the info from the other good sensors. That’s the situation you describe as common.
Rajaie
528i 5sp 06/00

[loach1]

Check eBay for vendors and decide for yourself. Some good reports, some not so good. Need to confirm your controller has gone south first, but typical symptoms can be found by doing a search - all reports on this forum are very similar.

[claudio512]

If so, whenever transmission fluid and filter is replaced... there is a straight pin that may drop when removing the transmission fluid filter and pin holds an electric moving part in place...


... la vendeta è dolce!!!

[H8LUUZN]

If you re-read Rajaie's post, you'll see what he posted is correct.



Picture courtesy of DKSF

[mikolasr]

Yes my cruise control is working fine - never had a problem with it. Apparently because I continued to drive with a bad left rear wheel speed sensor is has fouled up that function of the ABS module. I have removed the module and will be sending in for repair. I'll update with results once completed.

[frankya]

Um, lemme think.... oh...my firsthand expierience?
Cruise - OK
GAL - Nope
Speedo/odo - Nope
Trans - OK
Wiper speed - Nope

[frankya]

[KD]

After 2 months and 4 units I went with a new one. New one worked great.I spent as much for the new one by the time I paid shipping and mechanics to verify the units were not working. Plus my car didn't work for 2 months.

[loach1]

KD,

Sounds like you had an utterly miserable experience with the rebuild process. I too had problems with my rebuilt unit but now I know that it was all my fault because I had messed with one of the boards and used the wrong type of solder (acid-based flux) by mistake that eroded the work that they performed. I paid a little extra for my unit to be replaced with a good used one, which was programmed for my car and works fine. K-Bud had a lot of problems with www.autoecu.com but that was a mishandling issue that they eventually corrected. I know K-Bud was very frustrated by the whole thing but it sounds like one of their (ex)staff made a balls-up.

So, I'd be curious to know if you are an isolated case for a technical problem caused by the rebuild process - are there any others out there that have had problems? Or successes?

[MichaelD]

I just wanted to say thanks to those who suggested getting the module rebuilt. I sent ours to modulemaster and they rebuilt for $300. So far, it's been working fine, the speedo is working again, the abs and asc lights are off. Probably saved hundreds of dollars, if not thousands.

[DicMegaHurtz]

My mechanic told me I needed to replace the ABS unit and a wheel sensor. I decided to send the ABS to module masters. They returned it saying they could not determine that it needed to be rebuilt. I will be replacing the rear driver side wheel sensor since my speedometer is not working. I noticed that my brake light has gone from amber to red. Is it possible that some further damaged has occured from driving my X5 with a bad wheel sensor? Will replacing the wheel sensor reset my ABS light, triangle light and brake light? Thanks in advance for your help.

[Unregistered]

hi guys,
i have a 530i .i've had the usual problems with the abs and traction control lights. i had the abs module repaired only to find now that the traction control light is back on , the error code said it was the right rear wheel sensor was gone.i replaced it and the light was still on.i tried my abs module in a 535 and the abs and traction control lights came on,thinking the module was gone again i sent it to be repaired only for them to tell me it was perfect after a diagnostic.they told me it could be lateral or longitudinal sensors . bloody hell how many sensors are conected to these lights . any ideas would be great thanks

[JYGy2k5285spCT]

My abs computer failed about a year ago. But speedometer continued to work. Dealer replaced two sensors, abs light returned.dealer replaced the ABS computer (good willed it, because of replacings two sensor w/o fix) all is well. But speedo always worked,