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re: engine check light and brake fluid indicators in dash

I have a 1997 BMW 740il with ~ 132K miles. I need assistance with two items:

- the engine check indicator (yellow, far left in dash display)

- brake fluid warning (both the red indicator far right in dash display + centered via orange LED display)

remain on. One mechanic told me the brake fluid indicators are a false negative. The pads, rotors have been replace recently and the fluid is not low. I've had the check engine light checked several times. Apparently one mechanic told me he fixed it --- found a broken wire or missing ground -- but a second mechanic found the wire glued i.e. he implied the first mechanic never fixed the problem and did a cheat/ work-a-around to shut it off.

Bottom line: my wife won't drive it an I'll always wonder if I am ignoring a real problem.

Is some off the shelf H/W I can run to read the codes form the BMW computer and/or reset them? Is there anything I can do besides throw money at a reputable BMW mechanic (I don't trust dealers too much).

Shane

Reply to
gshanemiller
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Subsequently determined can purchase a tool to list and reset engine codes via product here:

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Reply to
gshanemiller

One final thought: the brake fluid indicator came on just after the last mechanic changed the pads and rotors. Now that probably mean the hoses with brake fluid were opened. Possibly something was not put back right - or there's a blockage or air in the system.

Reply to
gshanemiller

In article ,

This means the computer has logged an error. You need to find out what the error is, so you have some idea what the problem is.

So, fix it. There are several brake pressure switches that need to be open for the light to go out. Check them all with a meter until you find the one giving the spurious warning.

Do you know which wire it was, where?

It sounds like you need a competent mechanic before anything else.

Autozone will read the codes for you for free, although their reader won't do some of the BMW-specific codes. Once you have the codes, you at least have some notion of where to start looking for the problem.

The brake issue is a big one, though. Get the wiring diagram for your car (the .pdf is probably on the web somewhere) and start tracing with a meter.

--scott

Reply to
Scott Dorsey

You can drive down the corner parts store and buy any of several different brands and models of scan tools. Expect a good balance of features and price to come in at about $100-ish.

There is no need to open a brake line to replace pads and rotors.

Reply to
Jeff Strickland

The engine check light comes on steady yellow because it thinks your emissions are high. Mine does this after a lot of short runs because it wants a new 'lambda' sensor, but in reality the emissions are rock bottom. If the light is red or flashing and / or the display says "check engine", transmission etc. then either you have a failing battery or a big problem.

The brake warning is almost certainly because either your mechanic did not refit the pad wear sensors, or if they were activated (worn through), did not replace them (they cost a few dollars). Failure or poor connection to an ABS sensor can also bring the brake warning light on (yellow IIRC), but also brings on ABS, and DSC lights and confuses the satnav.

Sounds to me like your mechanic is either not very good and / or economical with the truth.

Reply to
R. Mark Clayton

I've ordered a code reader - reads both industry std. and BMW codes. Thank you other posters for tips. Nothing was done with the pad wear sensors - although as I novice I don't see why that would enable the fluid sensor.

Reply to
gshanemiller

I've ordered a code reader - reads both industry std. and BMW codes. Thank you other posters for tips. Nothing was done with the pad wear sensors - although as I novice I don't see why that would enable the fluid sensor.

Your instinct is correct, the wear sensor should turn on a different warning light than the Low Fluid sensor.

Taking a giant leap of faith here, my '94 325i Owner's Manual clearly indicates the fluid and wear warning lights as being different. The fluid light says BRAKE FLUID, and the wear warning is a circle with dotted lines around it at the 9:00 and 3:00 sides.

Your '97 7 Series could be different, but as an engineer I would expect the difference to be very minor if there is one.

Reply to
Jeff Strickland

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