My wife's 2004 XJ8 showed her a "transmission Fault" yellow warning and she immediately brought it home and shut it off. When I read the codes per the OBDII All I found was a P1316 and P1111. It also had a few miscellaneous cylinder misfire codes.

I started it and let it warm up and worked it through the gears and then drove it for about 5 miles. No trans warning at all. We have had the car for 4 yrs and put ~30K on it and never serviced the tranny. Car has 72K right now and I don't know when the trans fluid was changed last.

Is this likely just a sign that it needs fluid changed or signs of bad things to come?


Thanks for you help in advance.
Mike

 

Mike,

I'm attaching the X350 DTC Summaries manual, which gives definitions of the various Diagnostic Trouble Codes. There are additional and sometimes more complete definitions in the Workshop Manual, which you can download in six sections at these links:

http://www.mediafire.com/download/md...f+contents.pdf
http://www.mediafire.com/download/aa...nformation.pdf
http://www.mediafire.com/download/n3...2.+Chassis.pdf
http://www.mediafire.com/download/9b...Powertrain.pdf
http://www.mediafire.com/download/0i...Electrical.pdf
http://www.mediafire.com/download/4j...+and+Paint.pdf


The P1316 code indicates "Misfire excess emission," and it only triggers with at least one cylinder-specific code, such as a P0308 for cylinder 8.

The P1111 code simply means that all the system checks were successfully completed after the last time the memory was cleared, so ignore this code.

If the car seems to be running fine and the Transmission Fault warning happened when your wife first started the car, then the first thing I would suspect would be low battery voltage, which is a common cause of multiple, seemingly random codes.

I'm not an expert in the causes of Restricted Performance or Limp Home Mode, but if the engine really was misfiring severely, the Engine Control Module (ECM) may have taken measures to protect the engine and/or catalytic converters from permanent damage by restricting performance and possibly locking the gearbox in third or fifth gear. Maybe some of our members who have experienced one of these conditions can comment.

If only one cylinder was misfiring, a likely suspect would be its ignition coil. To test the coil, swap it with one from another cylinder and see if the DTC migrates to the other cylinder.

Bear in mind that a standard OBDII scanner can only read the P or Powertrain codes, but it is possible your car has one or more proprietary Jaguar codes stored: U (Undefined, mostly Network-related), B (Body) or C (Chassis). To read those codes requires a dealer-level system such as SDD, a high-end third-party system like AutoEnginuity with the added Jaguar extension, or a dedicated scanner like the iCarsoft i930 Jaguar version.

Cheers,

Don

 

Sometimes misfires annoy a gearbox. Fix the misfires and all will likely be OK. One cause of misfires is a bad coil. Another is a failing battery.

 

Thanks for the info guys?


Would 72K mi be a good time to have the trans fluid changed anyway?


Mike

 

Short answer, yes.

Although Jaguar and ZF intially claimed the 6HP26 transmission was "filled for life," ZF now states that, "Depending on the driving style, ZF therefore recommends a transmission oil change every 80,000 to 120,000 km (approx. 50,000 - 75,000 miles), or after 8 years at the latest."

See this document:

http://www.zf.com/media/media/docume...hselkit_EN.pdf

Jaguar advises that if the vehicle is subjected to "severe duty" the fluid should be changed every 48,000 km (30,000 miles).

There's a lot of info on the forum about which fluid to use. LifeGuard 6 is the only fluid ZF recommends. Search the forum for sources for the fluid, pan/filter, new pan screws, and electrical connector sleeve that should also be replaced. The Powertrain section of the Workshop Manual gives the necessary instructions for swapping the pan/filter and the temperature range in which the correct fluid level can be achieved.

Cheers,

Don