OBD2 Scanner and port mismatch

[LikeItHot]

I bought a Creader 3001 OBD2 diagnostic tool.  Tested in a friend's truck. Works great.  In my 2007 DMAX it powers up but gives a connection error.  Pins all tight and clean.  I realized only 6 of my 9 port wires meet a corresponding pin in the scanner jack.  Is that normal?

[HauptmannUK]

The C-Reader is a good piece of kit however it may well not work with your Isuzu.  Your Isuzu was made right at the end of the period when they were still using GM OBD1 protocol.  It will probably be using GM 8192 ALDL (Assembly Line Diagnostic Link).  There will be K-Line data on Pin 7, which certain modern scanners might read.  In the UK we have to use an old GM Tech2 scanner on old Isuzus.  Probably best to go to the Isuzu agent or to a mechanic who is regularly working on Isuzus and has found a compatible scanner.  Models 2007/8-on should be fully OBDII compliant.

[LikeItHot]

4 hours ago, HauptmannUK said:

The C-Reader is a good piece of kit however it may well not work with your Isuzu.  Your Isuzu was made right at the end of the period when they were still using GM OBD1 protocol.  It will probably be using GM 8192 ALDL (Assembly Line Diagnostic Link).  There will be K-Line data on Pin 7, which certain modern scanners might read.  In the UK we have to use an old GM Tech2 scanner on old Isuzus.  Probably best to go to the Isuzu agent or to a mechanic who is regularly working on Isuzus and has found a compatible scanner.  Models 2007/8-on should be fully OBDII compliant.

Thanks for the reply. The local Isuzu is not far I will stop by but are the obd1 and obd2 plugs not different shapes?  The former a rectangle and the latter a trapeze?  Note I checked https://www.outilsobdfacile.com/vehicle-list-compatible-obd2/isuzu

which indicates the vehicle should be obd2 (on the borderline as you said) and I consulted the user manual which revealed nothing.

[HauptmannUK]

4 hours ago, LikeItHot said:

Thanks for the reply. The local Isuzu is not far I will stop by but are the obd1 and obd2 plugs not different shapes?  The former a rectangle and the latter a trapeze?  Note I checked https://www.outilsobdfacile.com/vehicle-list-compatible-obd2/isuzu

which indicates the vehicle should be obd2 (on the borderline as you said) and I consulted the user manual which revealed nothing.

I was saying it will be using an OBD1 protocol - which it is.  It also appears to use K-Line (KeyWord Protocol 2000). See diagrams below which I managed to find. I think these were not fully OBD2 compliant until after 2008.  Thailand only required OBD2 from 2013, although nearly all cars were OBD2 long before that.

[LikeItHot]

On 6/10/2023 at 1:31 AM, HauptmannUK said:

I was saying it will be using an OBD1 protocol - which it is.  It also appears to use K-Line (KeyWord Protocol 2000). See diagrams below which I managed to find. I think these were not fully OBD2 compliant until after 2008.  Thailand only required OBD2 from 2013, although nearly all cars were OBD2 long before that.

So what's the solution? Get an OBF 1 reader with an OBD2 to OBD1 adapter plug?  Hard to imagine they put a new plug on and old computer.

[HauptmannUK]

2 hours ago, LikeItHot said:

So what's the solution? Get an OBF 1 reader with an OBD2 to OBD1 adapter plug?  Hard to imagine they put a new plug on and old computer.

There are plenty of older vehicles fitted with the J1962 16-pin connector that are not OBD2 compliant.

At the time your vehicle was made Isuzu were very close with GM and they were using the GM Tech2 scanner. Here in the UK I have an old Tech2 interface that plugs into a laptop with ALDL software on it. We use that on old GM and Isuzu Diesels. We also have a Launch X431 that I think also does them, but that's a £5k tool.  In the UK Diesels didn't need to be OBD2 (actually EOBD2) compliant until 2004 manufacture. So some 2006 registrations are not OBD2. Of course we don't see many nowadays. In Thailand aNything is possiBle until after about 2013.

Anyway, you just need access to a suitable scan tool. There must be some OBD2 scanners that will do it - as I said before, just go to a dealer or a mechanic who regularly works on these. He'll have something that reads it.