I am trying to read codes from a 1997 VdP and a 1996 XJ6, bith of which have a check engine light displayed.
I have tried a dedicated OBD2 scanner tool that I purchased years ago from Harbor Freight (Cen-Tech brand) and using scanner software on a laptop with a USB based ELM dongle.
Both of these methods produce "no codes present for both stored and pending.
I know the OBD2 port is powered since the Cen-Tech scanner powers up when plugged into the port.
Anyone have any suggestions as to why I am unable to read codes?

This is the scanner I have from Harbor Freight.

 

I also tried a WiFi ELM327 adapter and loaded an app on my phone called torque.
This also produced no codes even though the torque app said the connection to the adapter and the ECU was valid.

 

1996 was the first year of the OBDII standard and I have not had much luck scanning X300s with newer scan tools. I suspect they do not have the correct programming to interpret the primitive X300 diagnostic system.

The tool I usually try first on an X300 is an old Launch Creader VIII, maybe 15 years old. Even then, not every car cooperates. Sometimes multiple key-on key-off key-on cycles will help. Don't ask me why.

If you could find one of our members within driving distance who owns a working Jaguar PDU system, they might be able to successfully read both cars.

Perhaps other members will have better ideas.

Cheers,

Don

 

I have the same problem with my 1997 XJ6. The CEL is on but I don't get any OBDII error codes and can't clear it. The code reader I have is designed to also work specifically with Jaguars/Rovers. However I am getting error codes that begin with "FF" but cannot find any reference to them anywhere, even on the web. I assume they are Jaguar proprietary codes that Jaguar won't release to the public. Does have access to what they mean? I assume that is why I can't clear the CEL because some of them are always present in the background.

 

There was someone who on the X300 OBD 2 port when looking in found the pins on the car side bent

There are 2 power pins on the port , researching

One of them shares the fuse with the fuel pump relay control power but I can be wrong as brain scketchy

 

The previous Jaguar saloon, the XJ40, had a proprietary OBD1 diagnostic system. The diagnostic trouble codes were read by turning the key to the RUN position without starting the engine, then pressing and releasing the VCM button (Vehicle Condition Monitor). DTCs would display one at a time in the form of "FF" or "Fuel Fault" and a two-digit number. Here's the chart for the later XJ40s:



Cheers,

Don

 

Thanks Don for all of the great information. I have encountered FF codes with two digits but the ones I am seeing on my Jaguar code reader are longer like FF164600, FF169900, FF008FD00, FF800700, etc.

 

Is your JLR scan tool the iCarsoft or Foxwell? Just curious.

Those do not look like Mode $06 or hexidecimal codes or Ford codes.

Could you be scanning Freeze Frame data?

The only other possibility I can think of is that these are proprietary Lucas Sagem GEMS codes that your scan tool can read.

Don

 

I have an Ancel LD700 reader. I found this on the web "The Lucas Sagem GEMS codes were installed on Jaguar vehicles from 1996 to 1997." There were a lot more references to it in regards to Rover so I assume that is what they are.
Thanks Don for the help!