Hi all,

I am trying to connect a diagnostic tool to my XJS - without success. The car is a build in 9.1994, AJ16, VIN1967xx. The very same OBD scanner is working fine with another XJS.

The only reaction I get is a blinking LED at the cigarette lighter at each connection attempt.

Any suggestion what can be checked

 

Don't the OBD1 cars output codes through the computer screen?

 

What problem are you having with the car anyway?

 

I wonder if it would help to swap out the ECU with one from a 96?

 

Huh?

Isn't a 96 OBDII instead of OBDI? Either way unplugging either would reset the DTCs

 

Well, apart from a slightly erratic idle, I guess there is nothing wrong with my car.
However, I got myself one of the Jaguar IDS tools and was just about to play around a bit.
'Check engine' light is off, no DTC to be reported on the trip computer.

 

I thought all the AJ16 engined XJS were OBD2. If the early ones are not, would it become an OBD2 car if you swapped out the ECU for one from an OBD2 compliant car (such as 96) would it then respond to OBd2 tools?

 

Do me a favor. Have that IDS plugged in an ready to go. Turn the car off and when you click the software to start reading codes, count to one and then turn the car on. (Not ignition, just the car electronics). Sometimes I can't get it to read the trouble codes unless I turn the car on a second after I've instructed the IDS to check codes,

 

All cars with the AJ16 engine are OBD2.

Thanks for your reply Vee! Tried your suggestion several times. Unfortunately without success.

I see the security LED at the cigarette lighter bezel blinking whenever the reader tries to establish a connection. This LED is connected to the security module. I reckon that means there is at least a working electrical connection from the tester to the OBD2-socket and to the security module?

Any other ideas?

 

Oh I didn't notice that in your sig, my bad.

Anyways, tons of stuff can happen that the computer won't pick up, but I understand wanting to use your new tool.

Is it only unsteady at idle? Maybe check for some vacuum issues, throttle linkage, and IACV?

 

The only other suggestion I have is to swap ECUs.

I had your same problem, luckilyI had another ECU so I never troubleshot the problem. That ECU has other issues though. It wasn't reading the O2 sensors correctly, or at least wasn't able to read them flip flopping. I changed the sensors, no change. I changed the ECU and problem went away.

So basically it worked with a third party OBD2 reader, it just never was able to work with my IDS software.