740i ABS-DSC etc.

ABS DSC lights are on, speedo not working and temp guage at max. Leave the car for a day then all is normal. After it warms up, the problem returns. Help.

The ABS and DSC are influenced by the speedometer.
The issue of the temp gauge being full to the right and the speedo not working indicates a cluster issue maybe with earthing or the internals.
I would try and diagnose the instrument cluster first.

Originally Posted by a1exander

The ABS and DSC are influenced by the speedometer.

The wheel speed sensors influence everything ABS & DSC, so I'd do the 15 minute quick test of the wheel speed sensors pretty early on in the OP's diagnosis:
- ABS DSC diagnostic DIY

I had the exact problem it was my right rear wheel speed sensor. 50 bucks. Not hard to fix but not easy. Takes some finesse to get out it its a old rusty car.

Sent from my DROID4 using Bimmer App

Originally Posted by kofoedp

ABS DSC lights are on, speedo not working and temp guage at max. Leave the car for a day then all is normal. After it warms up, the problem returns. Help.

My 5er is doing the exact same thing, accompanied by transmission failsafe mode. Sent my ABS module to module masters and they said it was damaged beyond repair, so my assumption is you'll need a new module. I haven't bothered to put one in yet on the 5.

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I had a similar problem. No speedo, no cruise control, no analogue MPG gauge.

Tim put another ABS/DSC module on and everything works now. The module does have other faults though, so I'll be sending my unit off for repair.

Thanks
Mike

The speed sensors get dirty and their easy to clean i bought a little wire brush like 3/8 diameter so i could clean the hole out. I used brake cleaning fluid and it just takes alittle time to jack the car up and remove the wheels for easy access but you can look for frayed wires and its a good time to clean the inside of the wheels ..........Here is a good write-up
http://forums.bimmerforums.com/forum....php?t=1815681

Originally Posted by E36 Phantom

my assumption is you'll need a new module. I haven't bothered to put one in yet on the 5.

Here are all known replacement options:
- What are all known options when your ABS control module is bad (1)

Originally Posted by setconstr

Here is a good write-up
http://forums.bimmerforums.com/forum....php?t=1815681

Nice find. I'll add it to the canonical set of links for the trifecta:

- How to diagnose the BMW amber ABS BRAKE DSC/ASC trifecta or bifecta (1) & what are all known options when your ABS control module is bad (1) & Quick99Si's explanation of why the 10-minute wheel speed sensor diode-action quick test doesn't always work, especially on brand new non-OEM wheel speed sensors (1) (2) & explanations by 540iman as to why the fancy diagnostic tools very often (extremely often, like almost all the time) fail to properly diagnose the trifecta or bifecta (1) (2) (3) (4) (5) (6) & where to get the fancy schmancy diagnostic tools for free once you're aware of these limitations (1) & an ABS BRAKE DSC trifecta brake pressure sensor diagnostic DIY (1) & how to test and replace the steering angle sensor (1)