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OBD2 scanner
sevenhills
Forumite 4.9K Posts
in Motoring
You can get these from eBay for £4 from China. Is there anything to be gained by paying £40?
I just want to read and clear a spanner warning on my Zafira, but happy to pay more if it's useful.
I just want to read and clear a spanner warning on my Zafira, but happy to pay more if it's useful.
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On Vauxhall from memory, Put key in ignition, put foot on brake pad Al and hold down, Push in trip button and hold.
Turn on ignition and wait for 10 seconds.
Service light goes out.
I one touch windows has stopped.
Hold the down button on the windows and wait for 5 seconds after the hit the bottom.
Now hold the up button until window goes fully up and wait until you hear a sort of click or thud, then release the up buttons.
Then they work again.
ones for sub £20. I have cheap mini ones that cost £4 years ago and they work with generic software but that software
will not read all codes.
Sub £8 OBDII readers will work with the software for my car though if you dont mind a 2 week wait for delivery. Several
UK sellers buy them and resell for closer to £20.
Connect it to your phone and it gives easy to read fault codes
I tend to go the extra and get a manufacturer specific one that reads the airbags modules, ABS modules etc and can read and reset the codes there too.
The main modules/sets of diagnostic trouble codes are powertrain (P), body (B), chassis (C) and network (U).
The diagnostic trouble codes the different scanners read also change.
There are generic codes all manufacturers use (0) and manufacturer specific codes (1) then there are codes for transmission (3) and emissions (4).
A P0*** would be generic powertrain related.
A P1*** would be manufacturer specific powertrain related.
A B0*** would be body generic.
A B1*** would be body specific and so on.
Different types of scanners will read different modules and the software they contain will convert the different codes.
The system a dealer or specialist use will be able to read all the modules and convert both generic and specific codes.
A cheap scanner with some free or open sotfware will more then likely just read the powertrain module and convert the generic codes. As they aren't able to read specific codes they can often scramble these into false or misleading generic codes.
Then you have something inbetween, like a scanner that will read powertrain, body, network and chassis but only generic codes.
To throw some more confusion in the mix, different manufacturers use different connection protocols to the modules.
SAE J1850 – Ford
SAE J1850 PWM – General Motors
ISO 9141-2 – Asian and European vehicles, as well as Chrysler
ISO 14230 KWP2000 – Asian vehicles
ISO 15765-4/SAE J2480 (CAN) – US vehicles made after 2003
The vehicles ODB2 ports all appear the same but will use different pins within the port to read different things.
Most generic scanners will be able to detect which protocol the vehicle uses and read the module, though some won't.
I have found a cheap generic bluetooth scanner and some free/open software like TorquePro handy, more so in the past when cars had one or two modules, the main one being the powertrain.
These days cars have many modules and even if you got the correct code for a problem, the chances of fixing it yourself are very slim these days.