AFAIK,

- All facelift cars ie from VIN 179737 (4.0, 5.3 & 6.0) can display fault codes if the trip computer is fitted. If they have the standard analogue clock, you can just fit the trip computer in its place (with a replacement veneer panel)
- All 4.0 from VIN 194774 (April 1994) had OBDII fitted
- Late 6.0 (not sure if it was from same VIN 194774? ) had OBDII-style connectors (probably made sense economically from a manufacturing perspective) but they are not true OBDII. I have a 1996 6.0 with me at present and it has such a connector

Paul

 

What you have is a rather rare beast, not many 6.0's were made for '96 at least not many shipped state side. Yes both of my cars have the trip computer but unfortunately they won't help with anything but an engine code. Wish my '95 was the nice one being that it's the celebration edition that year.

 

This is false.

The facelift AJ16 4.0 engines will not send any codes to the trip computers.

I have had two 1996 AJ16 engine cars fitted with trip computers and they certainly have never revealed any codes whatsoever.

 

Tks Vee,

Do you think that at the point of intro of AJ16 and OBDII, the trip computer fault code display functionality was eliminated?

Paul

 

Yeah, I believe that.

I think it continues to function that way for the v12 model, or so I've read. I've never read anything confirming that the v12 models ever had a functioning OBD2 system, so I think the trip computer did double duty for those models. That's why I suspect it may do the same for the AJ6 models. AJ6 never got the OBD2.

You would need a special OBD2 scanner to pull ABS and Transmission codes for the AJ16 models. Only the standard "P" codes can be read by (virtually) all OBD2 readers.

 

Just a page from the '95 update literature which may or may not apply to the OBDII capability of the AJ16 powered cars:

Since it says preliminary it might not hold true.

 

It applies. 1995 XJS models with the AJ16 engine are OBD2 compliant. The way it reports fuel trims in the 1995 MY is suspect, but most everything else seems to work the way it should.

These cars are notoriously stingy with issuing codes, but when they are finally presented, its usually a great benefit to figure out the repair.

 

I also have a ‘94 car, with the 4.0L AJ16 engine. It has an OBD2 shaped port, but will it be compatible with the OBD2 standard?

I’ve had a read of the above posts, and I’m not sure, although I think they have been referencing the 6.0L V12.

 

N Bath,

Yes, your AJ16 car is OBDII compliant.

Cheers

Paul

 

Thanks, my mechanic has tried a number of readers on it, but can’t read any codes, any thoughts on what the issue might be?

 

I purchased the same unit from this seller. I replaced the battery and it works fine. I made a 3d printed box to hold the power supply and new board and CD reader. Costs- aside from the PDU itself (currently 550.00 for the ebay one), power supply was like 25.00, board shipped around 200.00, CD player, figure 20.00 on ebay, cable you need to make along with connectors- figure another 30.00 to 40.00. Total 835.00 I believe you need this unit to be able to work on the 6.0L engines in the later models with the ODBII connectors.