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[Webby the Bear]

Evening chaps, hope you're all well.

Over the last couple of weeks my cheap Autel Maxiscan scan-tool (MS509) has been getting quite a bit of use on my friends' cars 

I've had 3 separate engine management codes on 3 separate cars to deal with and I thought, if anyone's interested, I'd post up what they were and what I did to resolve the issue(s).

Before I do I had a brain wave to set up a thread (perhaps even a sticky if interest was enough) for folk to post up what codes (non-Omega) they've had come up on their cars and what they've done to resolve them especially as I've seen lots of threads (especially Vectra ones for some reason  ) where a fault code is posted and help is required. Plus it would give people interesting diagnostics to read.

What do you think? And if you do think its a good idea i'll go first with my 3 resolutions

[TheBoy]

The codes are just a clue as to what is wrong. Its just a small clue in to what the ECU thinks is wrong. In EOBD/OBDII world, some codes have multiple meanings for a given code.

Ideally, it needs live data to then take it further.

So, the codes give you clues as to which live data values you are interested in, which hopefully narrows down the fault.


Take Cliffo B's car, which left here a couple of hours ago. Complaint, TC light on (and EML on, and in limp mode). Engine fault codes, 2, both present, both 1700. One was a SVS from TCM, other was Unknown DTC. Fault codes from ABS ECU (which is where TC function exists on Omegas), was gear level position unknown. So the clue is to look in TCM ECU, and fault code for Range (Selector switch). So we now know to suspect the Range switch as the cause of all the primary and secondary complaints. Live data from Range switch showed, no matter what position the lever was in, all 4 position lines are inactive, an invalid combination. Quick check of the wiring diagrams shows the likely candidate, and fault then quickly located and resolved.


In essence, just working from fault codes alone is always guesswork, and what we expect from dealers and poorer garages, except on those codes that a specific marque suffers as a common fault. For example, if you showed me a 73/74 (0105 in ODBII world) code on a 2.5/3.0l Omega, but live data showed a reading, I'd not be looking at a faulty MAF, I'd be looking elsewhere, eg air leaks. On many other cars, I'd be suspecting MAF.

[Webby the Bear]

Thanks TB.

That was kinda the point to the thread.... people confirming they have a code and what action they have taken based on their diagnosis and research in to it.

For instance, one of the codes i had was P0670...Glow Plug circuit open. i googled the code and the procedure was to check the voltage coming in to the glow plug and timing how long it was for (to make sure the glow plug control module was kicking in on time AND for the correct amount of time). Then a resistance check of all glow plugs showed pot 1 to be nackered. replaced. job done.

so instead of the thread being ''i have code pxxxx, what can i do''... it'll be more ''i had pxxxx and fixed it by.....because of......''

just an idea. it might not be what people want to see anyway but just had a thought more from an interest point of view

[TheBoy]

Maybe, but the point I was making is the code alone is rarely sufficient, decent diagnostics to start replacing parts

[Webby the Bear]

Maybe, but the point I was making is the code alone is rarely sufficient, decent diagnostics to start replacing parts

Ok mate thanks 

[cem_devecioglu]

on many cases I have faced some codes were relevant some not..  so a generalisation may help sometimes and sometimes mislead.. speaking as a programmer, I would check the code but wont take it as a directive..


and honestly many car ECUs still have a long way to develop , not to tell bollix

[Webby the Bear]

Definitely agree Cem. That was what I wanted to achieve by posting. E.g. Code XYZ came up.....OBD said this was the problem and would fix it but it actually ended up being X that fixed it.