I got an Elm 327 usb tooday (to diag a bad misfire), plugged it in to my windows 7 laptop, a red light came on on it and it installed the drivers automaticly from windows update.

I installed OBDwiz, activated it and wennt to my car.

I plugged the Ellm in to the OBD port onn my car, ran OBDwiz and, Turned on ignition......nothing, it wont connect..

When the elm is plugged in to my car i only have the one red light on. Is thiis right or shhould i have more lights on.

I checked the com ports and changed everything to com1 (software and hardware) in case of a conflict. Still nothing.

Tried ProScan 5.9, activated it, cant connect either.

Same with ScannTool.net software.

Tried updating the drivers mannualy windoows tells me i have the latest driivers.

Tried diffrent baud rates, com ports, engine running, ignition on, nothing.

Have i brought a dodgy chinese copy or could my obd port on my car be broken ?

Any suggestions ?

Thanks

 

Was that ignition II (just before Start)? Engine running would also be OK.

32-bit or 64-bit Win7?

If you have something like hyperterminal it's fairly easy to see if the elm itself is working. Details via google I reckon, can't recall who posted them or when or where (here/UK).

 

ignition II and runinng, 32 bit win 7 ultimate, all updates.

Tried with windows update drivers

Drivers that came with it, and whql cert driivers, all same results.

When the elm is placed in the odb port of the car, do any lights on the elm light up apart from the red one when connected to the pc ?

Am also googling like crazy !!!!!

Tomorrow i'm going to plug it in to a vauxhall and see if it works on that.

 

So far so seemingly OK.

It should be a (virtual) COM port and at some (virtual) baud rate. Caution about assuming it's been found or hasn't.

Common baud rates are 9600 or 38400 but it will do much much faster (1Mbaud), at least on Linux.

If it's all connected and powered (as it seems), an OBD II app talks to the elm in ordinary (ASCII) lines of text. The elm will (when requested) then try to talk to the car (not in ASCII) and report what happened:

You <-----> PC <---- >elm <---> car

The elm has two connections as you know (USB & car) and both need power for their independent circuits - just confirming this, but it's why you need ign II or Engine Run.

I asked about hyperterminal because that way you can talk to the elm directly to show if that comms channel works. Supposing it does you then know the problem is in the elm <----> car part.

You might instead try some of the freebies from OBD 2007 at least one helps with diagnosing a link like this I think. Caution: I don't run Windows so this is heresay!

 

ok, using hyperterminal, i can "talk" to my elm, using atz command the elm replies ELM327 v1.4, so it's connnected to and "talking" to my laptop ok.

Which to me means the drivers and port setting are ok.

Any ideas what the next step is ?

If i plug the elm into the car with no pc attached should a light be on the elm ?

 

Look on ebay and there are dozens of varied elms with varied lights so you'd have to read up on yours / ask the seller.

A good place to go otherwise (not for the lights) is the elm327 datasheet as it tells you the commands and what they do. You can try ATSP variants and 0100 to see when your car responds and with what. I think it's here elmelectronics.com/DSheets/ELM327DS.pdf

It's been said that the early cars need PWM (ATSP1). I don't have that sort of car. Mine responds to ATSP3 (and for CAN but yours has no CAN at all).

If you can get a response to 0100 use ATDPN then you know what you're trying to get the OBD apps to do.

If nothing responds post back as it'll need more trying

 

If you have another car available, that's probably the quickest/easiest method to determine if it's the car or the elm. I have the bluetooth elm and it has all manner of green amber and red lights on one side that flicker and flutter when plugged into the car. I never pay attention to them. On my XJ, the port is behind the center console panel and configured so the lights point inboard, toward the tunnel, so they are useless to me anyway on that application. I normally leave it plugged in there, unless I need it on an S-type....and sometimes when I call on it, it won't go. If I reach down and re-seat it, all is well - even though it appears/feels properly seated.

 

thanks jagv8, i'm goinng to read the data sheet tonight (70 odd pages) to try and get a bit of an understanding of of it and will try on the car tomorrow.

I'll post back the results.

 

i thought of that and tried plugging unplugging and everything inbetween.

as regards the lights, i thought the may be a light lit up when iit was getting power from the car, cos when i plug the elm in with no pc i don't get any lights, i just hope it is the elm and not my car !!!!!

 

It's a pretty good bet, especially if you (like me) got by with a cheapie from Amazon or eBay. I use Torque, for Android and the notes with it cautioned everyone about the cheap copies not working and listed some preferred models, but I took my chances, as Amazon will take stuff back almost as easily as Walmart. So far, so good.

Dangit Police!!! you made me curious. OK...here's what I have, again, different unit from yours but it may be helpful to you. I get a steady red LED when plugged into the port: key off/key on, doesn't matter.
When I start the Torque application in my phone, and they start to communicate via BT, the red remains steady but the four LED's below it begin to flash in a roughly linear sequence, some fluttering between two and three...they are pretty rapid, but seem to be yellow-green-yellow-green
Here's a few pics of it in the 05 S-Typesorry, flash is on, off, or auto)

Key Off:





Key Onsame)



BT connected:

 

As I posted you'd have to find out what the lights on the specific one that was bought ought to do. No general rule because they vary so much. A power on light is of almost no use - you need to know about the comms protocol on the specific wire(s) and none have individual lights that I've seen.

If I had to guess I'd go for a problem with the pins (2 & 10) for PWM aka SCP, if indeed you need PWM. But why guess when you can test....

If you use it on another car you NEED to know it's the SAME comms protocol of course or you've proved nothing very much. (Common choices are ISO9141, KWP, PWM, VPW, CAN).

 

Or swing round to your local auto-parts store and ask for a complimentary read, if they can read it, your car port is fine, and problem is in the ELM.
The curiosity you stirred in me confirmed a P1111 on the wife's ride - so all is good!

 

they charge in the uk.

Jagv8, i couldn''t wait till tomorrow and been out to the car,

I tried the at command at sp 0 (search for protocol on next obd request)

then >03 (show codes)

Cant connect.

tried it a few times, cant connect

think i can read the voltage, does this look right

 

No such thing as a free OBD read over here

hmm, probably no read at a parts store at all.

 

I'd be happier if you did an 0100 as that's what should work (don't get into the OBD standard docs unless you have to).

Yeah, you know the power is there. 11.2 says the engine was off - I hope!!

If ATSP0 and then 0100 doesn't work, try both ATSP1 and ATSP3 each with 0100 and if it still doesn't work you're looking at the wiring.

edit:

It must already be part OK as the volts show pin 16 (batt+) and either/both of 4&5 (chassis & signal GNDs) are working.

For ATSP1 (PWM) you're asking pins 2&10 work as well. (They're "differential" i.e. the voltage between them is used.)

For ATSP3 (ISO) you need pin 7 to work.

 

Harrumph! Then I'd go back to trying other cars, if it won't work as advertised on two or three, he probably should review the return policy. Don't you have to have an operable OBDII port to pass MOT? Assuming so....it was ok when that was done...and unless someone's messed around in the area...chances are.....just saying'.......

 

Only worth trying other cars if they DEFINITELY use the same protocol i.e. pins.

Not needed and not tested for MoT

 

Engine was not running.

Ok, i'll do that in the morning, it's geting dark now and it's annoying/frustrating me, i'll start fresh in the morning.

thanks to everyonne for your help so far.

 

Thanks for clarifying, John, Wow! I thought MoT was a complete **** borescope!
Even numerous places here in the states have to have a P1111 (or equiv) to pass inspection. Fortunately, freedom still reigns here in Wise co...but our neighbors to the immediate South in the metroplex are so-plagued.

Good luck and hope you get it sorted tomorrow. Have you checked the list (sorry - think it may be a sticky...but there's a list of members who have OBDII readers and are willing to loan - can't remember exactly where) maybe someone nearby that could try a known-good reader to isolate your problem?

 

Instead of OBD we still do exhaust (tailpipe) gas analysis.

I believe new this year is that the MIL must self test correctly and then be off. Same for airbag & ABS etc.

The concept of a computer in a car is still a bit futuristic generally speaking over here. The idea of it running the car and there being many computers....