I just bought a OBD1 and I have never used one before, I figured it was time I learned. I pulled the panel on the drivers side and did not see the connector for it. I have no idea where to look next. I would appreciate it someone would help me out. Thanks!

 

93xjs6cyl,

Not quite sure what you mean by an OBDI. Are you sure you don't mean an OBDII reader? The AJ6-engined XJS is not OBDII compliant. It only has a Jaguar PDU port in the boot on the right hand side and will require a Jaguar PDU or equivalent system to read it.

Hope that helps

Paul

 

Paul,
I own both a OBD1 and an OBD11 reader and I have never used either. I know my 1993 is too old for the OBD11. So, I guess my question is how do I hook up my OBD1 to my car (1993 XJS 4.0 convertible). Also, a dumb question but what is a boot and where is that located? I take it the connector is different that what is used for the OBD11. Thanks!

 

Hi,
I too got caught up with the word boot the first time I heard it. It just means the trunk of the car.
Jomo

 

93xjs6cyl,

As Jomo has advised, the boot is the rear compartment of your car, the bit that Americans call a trunk.

As regards your OBDI reader, are you sure you have the right reader protocols and connector to fit a Jaguar? OBDI was a whole series of manufacturer-specific protocols and connectors. The Jaguar connector is designed for their proprietary PDU system. There is no such as a generic OBDI reader and connector.

If your system has the software to understand the Jaguar-specific protocols and the Jaguar PDU connector then you can connect to the PDU port in the boot.

Let us know how you get on!

Paul

 

I bought the Innova 3120 that does not appear to be compatible with this car. At least it will work on my other cars and truck. What system is suggested for this car? Thanks!

 

93xjs6cyl,

It's really difficult on a 93 car. You need the official Jaguar PDU system. I very much doubt that you have any chance of finding one! Many Jaguar garages have disposed of them and a few have found their way into private hands, but you won't find one!

The easiest thing to do is to just buy a facelift (post VIN 179737) trip computer and fit it in place of the clock. It uses the same wiring plug. You'll need to buy a new veneer to fit it. You could just buy the computer and fit it to the clock plug only when needed. Jaguar allowed the trip computer to display the fault codes if any have been thrown.

The only other way is to just take it to your Jaguar specialist who has a Jaguar PDU system when you need codes read.

Hope that helps

Paul

 

ptjs1,
I really appreciate you helping me out! I don't know if I am talking about the same thing, but my car has a small computer just above the radio that has thrown a code for a bad EGR sensor and sure enough the diaphragm was torn. So, I replaced it. It has trip, clock, gas usage and gas being burned at the time, ext.. Is that what you are talking about? If so, I already have one. I'm not sure how much it covers as far as codes though. Thanks!

 

If it's the same OBD1 built-in diagnostic computer as on the 93 XJ40 (I'm pretty sure it is!) it will display all the fault codes [if you have any] so no worries - throw away your reader, you don't need it!

Larry

 

First time I've ever had anything like it in any of my cars. Still need my scanner for my other vehicles. Thanks, again!

 

Looks like the question was answered just fine but sounds like you're still a bit mystified? Not surprising - the early days of electronics on cars were pretty muddy.

EFI and such has been around for quite a while and in the 1980s engine electronics became pretty common on cars. In 1991, California started to require that manufacturers provide outputs for diagnostic information but the bad news is that there was *no* common standard. Car manufacturers decided how they'd make it happen on their own so they used all sorts of methods - blinking lights, "magic" connectors to special computers and so on. That didn't work so well - even cars built by the same company had different ways to get the information out.

The chaos that resulted from those poorly thought out requirements is what finally resulted in the ODBII standard that was specified in 1994 and implemented in 1996. This finally resulted in a common connector and protocol that all cars sold in California had to have and that was adopted in the USA. As a standard it isn't awful, although it has plenty of issues, but it works OK for what it is.

What that means to us and our XJS cars is that diagnosing the ECU / EFI systems is a bit tough. The earlier cars only have to deal with fueling, which narrows down on the things that can go wrong but there's very little output to figure out what's wrong when a problem comes up - there's only a very basic output connector and the special diagnosis tools were amazingly expensive and as mentioned pretty much impossible to get any more.

The later cars like yours will output to the trip computer, which is kind of nice (at least until something goes wrong with it ). I think there is also another Jaguar diagnosis device that does a bit more than you can get from the computer but you can't get one, probably can't find one and it wouldn't really give you much more information than you can glean from what's already in the car. But none of the XJS systems are compatible with any test equipment from other manufacturers.

I'd suggest that it was not entirely a coincidence that the XJS was discontinued in the same year that ODBII became a requirement in the US.

I'm not sure if this is actually helpful but it was kind of fun to put together. I think its pretty close to correct.

 

chrisjbell,
I really glad that Jaguar had put this computer in my car! I really does come in handy. Like I said, it did throw out a code for a bad EGR and sure enough it was right. Thanks for taking the time to explain this all to me.