Car Diagnostic scanners - anybody use them?

[Ali]

I have had an appalling run of motoring these last 9 months running into the thousands, the root cause of this being misdignosis and finding a garage with proper diagnostic/obd software.

In late summer I had problems with my mercedes sprinter and some sensor equipment failing which I took to a local garage with a snap on diagnostic machine, tried changing parts with no luck. Was then told I really needed someone with the Mercedes Star diagnostic system to investigate, couldn't find a local garage who had it (and the ones that did wouldn't touch a commercial vehicle) and in the end had to take it to a garage many miles away, whilst crawling up the motorway with no torque and no speed. A drive I never want to do again. The garage managed to fix it, in the end replacing the very same sensors I had replaced and more importantly reconfiguring the ecu and fault codes with the proper software.

I have since had problems with a recent car change (2007 BMW 520D), with multiple problems and multiple misdiagnoses from my local trusted mechanic - who unfortunately has never owned any diagnostic equipment nor seems to have any interest in owning any. After several misdiagnoses and trying to solve a power loss problem he had to call in an 'expert' who used some sort of diagnostic equipment and subsequently found 23 fault codes (even though I never had any engine warning lights!).

I was just wondering if anybody else with an interest uses any diagnostic software and if it is worth investing in as I can't go on with having such problems in the future, has really cost me in all ways. Motoring never used to feel so hard

 

[pcb1962]

I bought one of these when my garage told me that my Mercedes was showing a gearbox fault code that I should get looked at by a main dealer. It showed me the fault code, which I then googled, and found that it was going to cost me upwards of a thousand pound for a job that takes about 2 hours, so it's still waiting to be fixed

 

[LancsRick]

You can get an OBD2 scanner for under a tenner that will link up to your smartphone. I've used it on mine a couple of times with the same result as the offering in the garage.

 

[acewoodturner]

I am fortunate that my workshop is next to a one man garage who has the scanners and he checks it for free although he doesn't always get the work to do. My main mechanic is about half a mile away and there is no problem with him sticking the van on a scanner. Main dealers around here (Fife) will charge about £90 plus vat to stick it on a scanner even if it only takes a couple of minutes. The trick is not just getting the codes, its how you interpret them which is just as important!

Mike

 

[mbartlett99]

I bought one of these when my garage told me that my Mercedes was showing a gearbox fault code that I should get looked at by a main dealer. It showed me the fault code, which I then googled, and found that it was going to cost me upwards of a thousand pound for a job that takes about 2 hours, so it's still waiting to be fixed

I got a similar looking unit for my range rover - ***** proof and has saved me 100s. Even if it was just to reset a suspension fault my local charge 50 quid so I'd say it was worth it. Do a little research though and get the correct model specific unit.

 

[xiphidius]

Invaluable Saved me a few pounds by knowing exactly what was wrong to present to the Stealers...in the vain hope they dont put me over a barrel and take advantage.lol

 

[Matt@]

I bought one couple of yrs ago, paid £250 for it. I like to do my own repairs to vehicles and its been invaluable. Best bit is it gives live data (with engine running or driving) which gives info relating to fuel trims etc. Be aware that fault codes should not be taken literally but they do give a good clue. An experienced use (not me!) will usually tell from a fault code what the problem most likely is. Myself, I google the fault code and go from there..

 

[jimmy_s]

I have an old VW Phaeton that has a lot of electronics on it. I bought a VAG Com diagnstics unit from Ross Tech for it and have found it invaluable for fault finding and repair as I do the majority of the work on the thing myself - as the garages hate working on it.
It would be hard to carry out any work on the car without proper diagnostics. You can have a number of fault codes from silly things - especially if you have had a flat battery so your 23 fault codes may not all be huge problems - 1 fault can bring up codes in a number of modules. I had a situation where I was driving along quite happy next thing I know the car crapped itself and the ABS, Traction Control and ESC warning lights lit up and it went into limp mode. I got the VAG Com on and found that the steering wheel angle sensor (clock spring) had gone. Because the car has so much electronics and modules the signal from the steering wheel angle sensor is sent to a number of other modules in the car so the ABS system, Stability Control, Traction Control and even the headlight control module all end up with error codes. With the diagnostics I could access the output from the steering wheel angle sensor and check its output with the engine running, turning the wheel. Also when I replaced it I had to calliberate the new sensor which you cant really do without a diagnostics unit.

I can't remember how much I paid for mine but its pretty good - I can access all the control modules including the ECU's/ Airbags etc. Without one I would be guessing as to the cause of my many woes with the old VW. You need to spend a bit of time getting to know how the control modules within the car operate and so on to make the best use of any diagnostics you buy.

 

[undergroundhunter]

Ok as a professional technician I would say go for it and buy one but please don't just assume it will tell you whats wrong with the vehicle, also google is a good resource but its not always right, the same fault code could have multiple causes. I have spent thousands of pounds and 10 years to get where I am and I don't know everything by any means. Generic EOBD readers have limited user really as they will only pick up EOBD codes, many manufactures are using specific codes these days and these will only be displayed by a specialist tool, because of this most indipendant garages are either specializing in one brand or are only doing basic diagnostic. If in doubt take it to a professional, i have seen vehicles have hundreds of pounds worth of parts thrown at them just because people assume the code reader will just tell them whats causing the fault.

Matt

 

[Matt@]

what I find with google is if you search a fault code you will invariably find threads on car forums which discuss the code and it becomes clear just how much you can reply on that fault code to be specific to a certain fault. VAG.COM by all accounts is excellent around £300 i think. OR a cheapo lead off Ebay and a pirate disc for a tenner and you can still sometimes get some access - worked once for me on a VAG then gave up

 

[undergroundhunter]

what I find with google is if you search a fault code you will invariably find threads on car forums which discuss the code and it becomes clear just how much you can reply on that fault code to be specific to a certain fault. VAG.COM by all accounts is excellent around £300 i think. OR a cheapo lead off Ebay and a pirate disc for a tenner and you can still sometimes get some access - worked once for me on a VAG then gave up

Here is an excellent example, I had a polo in the other day with a MAP sensor fault, the little old ladies local garage had replaced the MAP sensor and it still had a fault, brought it in to us (main dealer) within 5 mins I had diagnosed a wiring fault and an hour later had found the broken wire and fixed the fault. The first garage charged £150 inc diag for their "repair", we charged £100 and we fixed it first time with no parts needed. The garage it had been to had a £6000 snap on scanner that gave him all the same information I had except I used my training and knowledge to make an accurate diagnosis. If you google the code it came up with internal MAP sensor faults and a replacement fixes the fault, but not in this case. My point is accurate diagnosis is nearly always cheaper than guessing which is ultimately what googling the fault code is.

 

[DiscoStu]

I have an IID tool which is a fabulous bit of kit but it's really aimed at land rovers. It can work with all of the cars ecu's and not just the engine. Plus you can enable and disable functions and read various live values.


Sent from my iPhone using Tapatalk

 

[fishe_17]

You can get an OBD2 scanner for under a tenner that will link up to your smartphone. I've used it on mine a couple of times with the same result as the offering in the garage.

second this!

 

[Ollie78]

I have one that will tell me basic stuff on my smartphone but it is pretty simple. For my imported nissan I bought Nissan data scan and a wire which was certainly worthwhile and is extremely comprehensive.
When I had a golf I got vagcomm lite which was useful.
I would say get something specific to your car / brand if you can.

Worth it even if you check it before taking it to a garage.

Ollie

 

[guineafowl21]

second this!

Firstly, holy thread revival, Batman!

A basic ELM27 type/smartphone OBD scanner will tell you generic, generally emissions-related faults in the engine.

A garage-level/manufacturer specific scanner will talk to all the ECUs in detail, give live data and even be able to activate functions for diagnostics. A totally different beast, and costing orders of magnitude more.

For things like JLR vehicles you can get aftermarket compromise scanners, like the Lynx, iCarsoft or GapIID which have in-between capabilities, and can be extremely useful. These would be the best compromise if you can get a version for your vehicle.

 

[Spectric]

Vehicle diagnostic scanners do not come cheap, but also you have to pay for updates on a regular basis so unless you are a garage and can make it pay then just not worth the outlay. Our local garage uses one that set him back nearly 10K and it is only as good as the user and what data the vehicle can provide. There is another system on the market, a local auto electrician rates it and this uses an interface module with your own laptop and it is a pay to use system so I think you pay by the hour which may be another option. Recently when my Peugeot broke down, the RAC's diagnostics showed "internal BCI fault" but the guy said it may not be that module, it could be a connector and is something they see a lot of. Like so many tools, to get the best out of them the users experience and knowledge can play a vital role.

Having worked in automotive / Agricultural electronics and back in the days when automotive were using RCON's it was so evident that complexity was causing many issues and it would get worse, a simple thing like a high impedance ground could show up as one of many faults in diagnostics and cost the user money with parts that were not required. Agricultural have got it right in that diagnostic's are built into the tractor, the onboard displays can be used to display information that can be used to diagnose a fault.

As @undergroundhunter said, he had a broken wire, no diagnostic system is going to say " you have a broken MAP sensor wire" it can only inform you that the MAP sensor signal is at fault, down to you to find out why.

 

[Pedronicus]

I would think that there is nothing a dealer or mechanic would like better than a customer rocking up with a load of codes from his reader and then insisting that the relevant parts be changed 'cos Google says so!

This used to happen to me when I was working as people would treat info gained from t'internet for faults on their heating systems as gospel and told me which parts to change and how much I should charge them. I tried to help them out but, with some, I had to advise a caveat that "You told me what to change so if it doesn't fix the problem I still want paying!"

 

[Jameshow]

I bought one couple of yrs ago, paid £250 for it. I like to do my own repairs to vehicles and its been invaluable. Best bit is it gives live data (with engine running or driving) which gives info relating to fuel trims etc. Be aware that fault codes should not be taken literally but they do give a good clue. An experienced use (not me!) will usually tell from a fault code what the problem most likely is. Myself, I google the fault code and go from there..

Which one???

 

[sammy.se]

5 year old thread, but that's OK.
For my VW and Audi, I bought OBDeleven. £80 all in and allows me to re-code like VAG.COM
brilliant kit, BUT, it only works when you have data/wifi, otherwise it's a useless lump.

 

[Spectric]

How many people have actually seen either the strategy or calibration file for a modern engine, the number of parameters is mind boggling and with so many interactions you can understand why some faults become masked by others.