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Diagnostic scan - What are they and why do I need one?

40K views 23 replies 20 participants last post by  apps28 
#1 · (Edited by Moderator)
This is becoming a very recurrent theme with forum posters so I have posted this to save the information being repeated over and over!

What should I do if my BMW has a fault light on the dash board that will not go off?

If you cant rectify the problem then a diagnostic scan is the answer

The engine light is back on and I only just had the car serviced?!

An OBD2 scan (or OBD 1 for pre 95 cars) is needed to read the codes properly.

My car has running problems and I just cant work out what it could be?? what should I do?

Get a diagnostic scan done by a competent local garage. Most will have the equipment to scan the vast majority of BMWs. Estimated cost should be between £25-£40~ depending on location and other factors. Get a printout (if possible) or handwritten list of the exact fault codes the ECU gave and then post them up on here.
It makes helping you out remotely a lot easier...


I dont know....is it worth it to get one of these OBD diagnostic scans done?? My car only runs badly internittently?!

YES, it is! The ECU stores fault codes as various components on the car report them during runtime.
So even if your fault is intermittent, there is a good chance that the ECU will have logged an error code during the fault period and this can save a lot of legwork and £££££.



In summary, newer BMWs have even more sensors and electronic reporting systems...so there is an even greater likelihood of a fault being reported.
With slightly older cars...it is still a BMW and as such is clever by nature! The fault codes can really be a great signpost to fixing any problems that are present on your car.

Examples//
A faulty ABS sensor that gives you an ABS warning light on your dash will report itself to the ECU, with many models actually telling the computer which sensor (which wheel) is at fault.

Your car is drinking (stupidly expensive) fuel like there is no tomorrow. Your pretty sure it never used to be this bad!!
What could it be?

There is a good chance that the Lambda sensor(s) (commonly known as the O2 sensor(s) ) could be at fault.
This will be logged in the ECU as a fault and will confirm if that is the problem.

This list will be added to as I have time!
 
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#8 ·
#11 ·
From experience I would recommend buying a K+DCAN cable from ebay and use that in conjunction with a dedicated software like INPA to diagnose and reset faults. BMW`s may register faults from time to time even if it`s not a permanent error. They may be electrical glitches that need to be reset/erased.
 
#14 ·
Hi anyone help with these codes.

Fault codes on C110 code reader
0000 Transport Mode Active
00, 01, 78, 47 No Found!
00, 01, 08, 09 No Found!
00, 01, B0, 48 No Found!
00, 01, 20, 08 No Found!
00, 01, 03, 18 No Found!
00, 01, 17, 5F No Found!
00, 01, 1F, 05 No Found!
Garry
 
#15 ·
Does anyone have any experience of the BMW Software INPA? I recently installed it and it seems to work fine as I can read the fault codes etc, however it came with a couple of additional applications such as NCS Expert.
What I am looking for is any information / tutorial / manuals on how to use this all!!

I had thought that I could use them to also actually find what part is at fault or am I on the garden path here?
many thanks in advance
Dave
 
#17 ·
Thanks, I realise that now. Is there any software that will help once you have the fault codes?
e.g. my 320d E46 shows the fault code that points to low pressure in the common rail. What I want to know is if there is a software tool that can test suspected faulty parts.
 
#21 ·
I know this is an old post but if your looking for a decent code reader/diagnostic tool, try iCarsoft, they do a range to cover most makes, as good as Snap on tool except its Make/model specfic, and does pretty much all that 2 grand snap on does for around £135 on ebay go to an official seller so you get proper support
 
#22 ·

Thought will let you know guys if anyone in need. Got the above kit and it works perfectly! Amazing and very happy! Comes with a handy full software suite and installation guide too so no downloading software here and there off internet forums to get it to work, spending hours to research, it's an all-in-one package, very friendly technical suppirt 😊
 
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