OBD Scanner

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OBD Scanner

Post by kjwhitehead »

I am attempting to diagnose issues with my 2001 BMW 740iL. I could not reset the oil change dash indicator. I took it to my mechanic who hooked up his scanner to the OBD-II port and he could not get a valid connection. The connection failed. I had an alternator failure and it was replaced along with the battery. The button to open the trunk no longer works.

Prior to this, I noticed that the seat, steering wheel, mirror memory no longer can be reset and it looks like the auto night mirror no longer dims when vehicles are behind me.

I am trying to figure out what to check first to repair these issues. Any thoughts? Where can I get a scanner to try and get a connection?

2001 740iL Sport

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Post by alken »

Kevin -

I'm sure a couple of the resident techs will elaborate on my basic understanding of the diagnostic system. As I understand it, if the battery is disconnected for an extended period of time, the OBD system requires a set number of drive cycles before it will communicate.

If someone can more clearly explain this (or contradict it if I'm out of touch on the subject), please do.

Beyond that, it certainly can't hurt to check fuses. Given the electrical work, perhaps there is one or more blown fuses that are causing the various malfunctions.

As for where to buy a scan tool, we are a stocking dealer for Peake Research scan/reset tools. These also will reset the service interval indicator. The Peake Tools are not a generic OBDII reader - rather, they will read BMW-Specific factory codes.

We're local, and can certainly arrange pick up.

You can see our full selection at www.bmwscantools.com.


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Post by RAYADAM »

check fuse #27 in the Ebox under the hood. if the fuse is ok,check to see if power (B+) is present at the fuse. you may have a main circuit fuse failure which is a (Fuse#110)80A.located in the RF door sill area under the carpet(any water leaks?) . I have seen the 80A fuse go bad several times


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Post by victory1auto »

My guess is that after you rectify the electrical problem you will restore scanner communication. Unlike OBDI, the OBDII on your car has a hot-at-all-times pin on the scanner connector.


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Post by RAYADAM »

The Fuse #27 circuit provides power to the OBDII port,if fuse is blown and/or does not have B+ ,scan tools will not work.

F110 provides power to F#27,also on the circuit is the power seats,trunk lock,etc...

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Post by pietern »

Kevin was your problem resolved?

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Generic OBDII Scan Tools

Post by Manta69 »

I can also say (just putitng my $.02 in) that Generic OBDII scan tools often will not work properly with many European vehicles. They will establish communication, so long as the data BUS isn't faulty and the 16 pin OBDII connector has proper power and ground, however the data retrieved may wind up being skewed or inaccurate. The I/M inspection readiness monitor data will be correct, however, in order to comply with Federal I/M testing standards.

The Peake tool will properly get codes out of OBDII equipped BMW vehicles because it is made and programmed specifically for them. Also, after market scan tools with BMW software will work as well. Just the DIY handheld 'Global' testers/scanners may have a problem, because their software isn't manufacturer specific.


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