mickeyw

OBDII readers - what can you tell me (slightly O/T)

13 posts in this topic

Evening all, I hope this isn't too O/T asking about vehicle diagnostics on a non-LR. I know there are many folk on here that work on other marques, so am hoping they can provide some information.

When I'm not driving my 110, I run around in a Eurobox. Unlike the 110 it has advanced electronics on board, and this week it's lit up an engine fault light on the dash.

A little reading tells me said light could be pointing to any one of a whole host of sensors, that apparently can be identified with an OBDII reader, or take it to the stealer, or other knowledgeable garage outfit.

Said Eurobox is a 2007 Corsa, so hardly so new that I can't service it myself. After all I don't pay anyone to work on the LR, so happy to have a go at this problem too.

Anyway back on the off-topic topic.

What knowledge can anyone share with me regarding home user OBDII devices?

I've seen a whole load of readers/reset tools on eblag and Amazon. They all look similar, but vary in price enormously. I have no idea what I am looking at really, but from what I can determine there are some that are car brand specific, and some that cover all, some that can just read fault codes, and some that can reset them too.

I have a laptop that I use for Megajolt and Rovergauge, so wonder if there's software that would do the job once I buy a cable. Obviously anything freeware/ open source would be handy.

Over to you knowledgeable people.

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OBD is a bit of a can of worms although it is standardising.

Basically the US mandated the MIL light back in the 90s for certain emissions related faults. They also mandated that certain faults be logged in some form of diagnostics port. Manufacturers went their own way, they already had built in electrical buses so tacked the diagnostics onto that. This meant that years ago depending on which manufacturer you used you had a different electrical protocol to talk to get the same information.

Move on a few years to the 2000s and Europe got involved and everyone started standardising that all OBD ports must support at least CAN (in the OBD-II spec), they could provide other protocols but must support the minimum information over CANBUS.

In relation to your question if the MIL light is illuminated then any generic OBD reader should be able to tell you what the problem is as that is usually illuminated when an emissions related fault code is generated. That may or may not help you narrow down the problem - this webpage gives a decent overview. Some generic code readers can read a decent amount of manufacturers specific stuff but there is no requirement that the manufacturer expose fault codes on the generic OBD system.

Chances are that any fault code reader would work - the ELM327s seem to be quite a popular choice.

Whereabouts are you actually based? I've got an IID Tool BT for the L322 and that can supposedly read and reset faults on any vehicle - but has the capability of editing a load of configuration settings for my Range Rover. If you're not too far we could try it out.

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As above, any of the standard ones should work for you, and point you towards most issues.

You only need the really expensive kit if there is something marque-specific wrong and not showing up with standard OBD2 codes.

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You only need the really expensive kit if there is something marque-specific wrong and not showing up with standard OBD2 codes.

I think you need the manufacturer specific ones to reset fault codes related to SRS (airbags etc).

I've got a cheap fault code reader - ELM based from ebay and it works OK for reading engine parameters. It's bluetooth, and there's an app on android called Torque that reads / resets codes.

If it's engine related, there's a good chance that if you fix the cause the light will go away. For most cars there's also a way to read the specific fault without a reader.

Not sure which specific Corsa yours is, but something like this:

http://www.corsa-c.co.uk/forum/showthread.php?134139-How-to-do-the-pedal-test-and-what-the-Fault-codes-mean

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I use torque on my android phone / tablet with a cheap Bluetooth adaptor. The app was a couple of quid and the adaptor was about 15.

Works on my 2006 citroen and 2010 isuzu. The expensive adaptors have better stream rates etc but the cheap one has always worked for the basic stuff I do.

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or if you want something that will work on anything ( except apparently the p38 but thats a oddity) try the autocom. bit more pricey but it can do just about anything, and the test function is useful, for instance my dads van had a aircon fault, last time he had this on a different van it was a broken wire stopping the cluch engaging, so first thing i did was put the autocom in aircon test mode it ran through all the tests and came back with no fault then i checked the fault codes and it came back aircon low pressure. had it regassed and all is ok. yes a elm or similar would have been ok, but a decent one has paid for itself many times over.

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I also use Torque Pro on my phone (or tablet) with a cheap ELM327 adapter (I have a few adapters, all cheap, all elm327, all vary in connection speed)

Unfortunately the ELM327 wont work with a TD5, but it does work with fords, so the 2.4 and 2.2 TDCI work great.

With Torque Pro I can monitor most engine sensors, and read and clear fault codes.

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i have a astra van as a daily. so unforunalty am only too familier with the engine lights. maybe worth having a quick google to see if you use pedal check to bring the codes up. :)

opps! jon has already mention that. :blush:

Edited by Landy-Novice

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OBD is a bit of a can of worms although it is standardising.

Basically the US mandated the MIL light back in the 90s for certain emissions related faults. They also mandated that certain faults be logged in some form of diagnostics port. Manufacturers went their own way, they already had built in electrical buses so tacked the diagnostics onto that. This meant that years ago depending on which manufacturer you used you had a different electrical protocol to talk to get the same information.

Move on a few years to the 2000s and Europe got involved and everyone started standardising that all OBD ports must support at least CAN (in the OBD-II spec), they could provide other protocols but must support the minimum information over CANBUS.

In relation to your question if the MIL light is illuminated then any generic OBD reader should be able to tell you what the problem is as that is usually illuminated when an emissions related fault code is generated. That may or may not help you narrow down the problem - this webpage gives a decent overview. Some generic code readers can read a decent amount of manufacturers specific stuff but there is no requirement that the manufacturer expose fault codes on the generic OBD system.

Chances are that any fault code reader would work - the ELM327s seem to be quite a popular choice.

Whereabouts are you actually based? I've got an IID Tool BT for the L322 and that can supposedly read and reset faults on any vehicle - but has the capability of editing a load of configuration settings for my Range Rover. If you're not too far we could try it out.

Thanks for all that information Ed.

I'm close to Gatwick, so not a million miles from you; however I have a couple of more local options to explore first. Thanks for your offer though - I may still take you up on it yet.

I think you need the manufacturer specific ones to reset fault codes related to SRS (airbags etc).

I've got a cheap fault code reader - ELM based from ebay and it works OK for reading engine parameters. It's bluetooth, and there's an app on android called Torque that reads / resets codes.

If it's engine related, there's a good chance that if you fix the cause the light will go away. For most cars there's also a way to read the specific fault without a reader.

Not sure which specific Corsa yours is, but something like this:

http://www.corsa-c.co.uk/forum/showthread.php?134139-How-to-do-the-pedal-test-and-what-the-Fault-codes-mean

The car is a 57 reg Corsa D with the Z12XEP engine.

I wasn't aware of the pedal test, although having just reset the service indicator (after servicing it ;) ) I can see the method works along the same line.

I'll see if I can have a go with this method later. Thanks for the link.

I also use Torque Pro on my phone (or tablet) with a cheap ELM327 adapter (I have a few adapters, all cheap, all elm327, all vary in connection speed)

Unfortunately the ELM327 wont work with a TD5, but it does work with fords, so the 2.4 and 2.2 TDCI work great.

With Torque Pro I can monitor most engine sensors, and read and clear fault codes.

I like the idea of software on a laptop or tablet. I'm not sure if Torque Pro is available for Windows, but there do seem to be a number of other OBD tools in the Windows store.

The ELM327 seems quite prolific on the bay, and from a little reading it seems the most commonly copied chip from China. I get the idea the £25 upward ones are more likely to be genuine. Is there a specific source anyone can vouch for as being OK. It seems the firmware on the later ELM chip is harder to forge. I have no issues with a cheap version as long as it actually works.

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I bought a £50 Chinese jobby of Ebay and it does loads of stuff. I can even use it to help bleed the brakes on my car/

Looking at it now, on the Corsa, it will scan and reset codes for engine, brakes, instruments, climate, gearbox, immobiliser, restraints, multfunction (park assist, power steering, radio, trailer interface) and service light reset.

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Thanks for all that information Ed.

I'm close to Gatwick, so not a million miles from you; however I have a couple of more local options to explore first. Thanks for your offer though - I may still take you up on it yet.

No worries, I've spent quite a bit of time researching it for various work things.

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OK, so I thought I'd take a punt with a cheapo Bluetooth OBD reader. It's gone up in price slightly since I bought it, but still dirt cheap.

http://www.ebay.co.uk/itm/282033619063

Anyway, I used this with Car Scanner (free) from the Windows store, and it connected quickly to my phone and the car. It can tell me a squillion and one things that I don't understand

However it identified two logged faults relating to the post-cat oxygen sensor.

P0036: HO2S Heater Control C ircuit (Bank 1 Sensor 2)

P0141: O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)

Things to check from what I have read are fuses, connector to the sensor intact & not corroded inside. If that doesn't reveal anything I'll remove the sensor and check the heater circuit for continuity before possible replacement if it appears dead. Hopefully the engine light will go out once this is sorted.

Now where did I put my round tuit???

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I just noticed that I hadn't updated this thread.

I actually fixed this problem some months ago. It turned out the post-cat O2 sensor was toast.

After dabbling with a cheap replacement from Euro Car parts that didn't work out of the box (no the box wasn't blue ;) ) I ended up with a Bosch item that looked identical to the original and worked perfectly. I then reset the logged faults using the reader and phone app.

So, £5 for a code reader, £70 odd for the sensor (massively discounted as they had sold me a dud to begin with) and I'm all sorted. I also purchased the paid for version of phone app (only a couple of quid) as I believe it's worth recognising the work of the developers of a good product that has saved me time and money.

Link to the app here in case anyone else is interested https://www.microsoft.com/en-gb/store/p/car-scanner-pro/9nblggh5rv45

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