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I have a 1994 Jaguar XJS and the transmission is currently in fail/safe mode. The alternator was recently replaced and I'm guessing it has something to do with that. Nevertheless, the transmission specialist I brought the car to said he can't read the computer codes on the 1994 model because it doesn't accept the OBDII scanner. Can any help and recommend how I can read the codes?
If you do a little reading on the forum, you'll find out how to get the codes to display on the clock screen.
Thanks
The only thing that I read was that if you leave the ingition in the on position with the engine turned off, it should work. If you can share a link or provide additional info , it would be appreciated. Thanks !
Early '94's are an OBD1 system, so nothing to scan. The fault codes appear on the clock screen when the ignition switch is turned to "on" position. I f you disconnect the battery ground cable and wait @30 seconds, then turn the ignition back on, you will see FFcodes. However, I don't recall there is a FFcode for the trans limp-home mode. Failure of this type is commonly a fault of the TPS, or the TPS wiring. I've had recent experience with the TPS wiring causing a tranny fault and found the TPS thick with oil, as well as the wire harness. A thorough cleaning of all and a length of plastic, corrugated tubing that is split to slide it onto a harness cured the issue after reconnecting the battery ground cable. You may have to replace the TPS which ain't cheap (Moss Motors $235) and tough to remove unless you take the throttle body assy off. Good luck!
Dave in AZ
It is possible to read the ABS and TCM in a 94 XJS using the old WDS or IDS dealer tool (or Genrad GDS-5xx), but you will need an adaptor cable to plug into the diagnostic socket.
You read the car using the 95/96 XJS protocol, as the ABS & TCM modules are the same as the 94.
Alternatively tapping the Orange wire of the '94 diagnostic connector to pin 7 of the DLC cable of the WDS/IDS/GDS will also work, but then you need to sort out power connections separately.
...You may have to replace the TPS which ain't cheap (Moss Motors $235) and tough to remove unless you take the throttle body assy off. Good luck!
Dave in AZ
I believe the two screws securing it are 5.5mm. I scared the dog with my foul language while removing/replacing mine. Good luck indeed!
The only thing that I read was that if you leave the ingition in the on position with the engine turned off, it should work. If you can share a link or provide additional info , it would be appreciated. Thanks !
It is possible to read the ABS and TCM in a 94 XJS using the old WDS or IDS dealer tool (or Genrad GDS-5xx), but you will need an adaptor cable to plug into the diagnostic socket.
You read the car using the 95/96 XJS protocol, as the ABS & TCM modules are the same as the 94.
Alternatively tapping the Orange wire of the '94 diagnostic connector to pin 7 of the DLC cable of the WDS/IDS/GDS will also work, but then you need to sort out power connections separately.
Hello, would you by any chance know of a source to purchase the adapter from? Also, is the Genrad GDS-5xx a scan tool that is readily available? I can't say that I've come across that branding before. I do have an older OBDII with adapters for Ford, GM and Chrysler but I'm sure it wouldn't work with the proprietary Jaguar PID's.
Some 15 years ago when I was working on an '88 H&E that we owned I had purchased from and old former independent Jaguar Mechanic that had owned a shop some of the original Jag service manuals. The large green ones along with the H&E supplemental red colored volume. If only I had known, I would have bought from him the PDU or JDS that I'm sure he had since he was selling off many Jaguar specific tools as well.
Any suggestions that you may have for a code reader that will work with the adapter?
I have a '94 that occasionally will illuminate the trans fault lamp and start to shift hard. I would like to see if there has been a code logged that may help to point me in the right direction instead of just guessing at it being an EPC solenoid or such.
Thanks, for any assistance with this that you might have.
Jagman99r, is your car a 4.0 or 6.0? Makes a big difference. 4.0s can be read by some aftermarket scan tools, but 6.0s can only be read by the PDU. WDS says it can do it, but it cannot; I've tried and I have both a PDU and a WDS. Your info says you have a 95. I believe they all came with an OBD2 type connector under the dash, but the 6.0 cannot be read by any aftermarket scanner. Some 95s MAY have come with the old round connector; again, 6.0s can only be read by a PDU.
EDIT: IF you have a 6.0, trans blink codes can be had by shorting one pin on the TCU to ground. The trans warning light blinks the codes, they do not display on the trip computer. The TCU is buried behind a rear passenger side panel, and is a PITA to access.
Jon
Hello Jon, thanks for the reply. I have both a '94 and a '95. Both are 6.0L engines. As far as I can tell the only one to come with an OBDII connection in the '96 4.0L. So neither of mine are compatible. The TCM in both of these is in the boot since they are convertibles. So I guess that makes it a little easier. I suppose that you ground the pin and then turn on the ignition to view the trans code blinks? Wish I could find a PDU. Reminds me of when we would short two terminals of the EECIV system of the old '80's Fords and you could get the mil lamp to flash out a code number for you. Sure did like the scanner when I finally got one.
You also would need the base station to load the PDU for each specific test you want to do. There is a guy in the Neatherlands making the circuit board you need to interface with a specific IDE cdrom drive. That is the route I went. You also need to have a power supply for the board and make the interconnects. The PDU is a PITA to use, but it has helped me diagnose things on my car I couldn't do otherwise.
Do a search on this site for "PDU dropbox", and a thread will come up on the whole mess you need to go thru to use a PDU.
Jon
You also would need the base station to load the PDU for each specific test you want to do. There is a guy in the Neatherlands making the circuit board you need to interface with a specific IDE cdrom drive. That is the route I went. You also need to have a power supply for the board and make the interconnects. The PDU is a PITA to use, but it has helped me diagnose things on my car I couldn't do otherwise.
Do a search on this site for "PDU dropbox", and a thread will come up on the whole mess you need to go thru to use a PDU.
Jon
Yeah, I went and checked it out. Seems a bit pricey for something that they can't say wether it works or not. Could be an expensive paper weight. I could change all the solenoids and more for that amount. Thanks for the heads up though. I guess I would need a lot more than just the PDU anyway so it probably would be useless for me at this point.
You don't mention in your profile if the car is a V12 or Straight Six.
That might make a difference in where you can read the codes.
Not likely the codes are readable on the digital clock on a six since they didn't come standard on them.
Yeah, I went and checked it out. Seems a bit pricey for something that they can't say wether it works or not. Could be an expensive paper weight. I could change all the solenoids and more for that amount. Thanks for the heads up though. I guess I would need a lot more than just the PDU anyway so it probably would be useless for me at this point.
Yeah, expensive, but it helped me diagnose issues with my ABS (late Teves style), seat memory, and calibrating a new throttle position sensor. The late ABS (1995.25 MY and up) can't be diagnosed any other way, nor can the seat memory system. There are ways around with blink codes for the tranny, and of course generic engine codes on the trip computer.
Jon
OBD Scanner Help!! 94 Jag XJS
