After a couple of days detailing the engine bay with a spray bottle of TSP and another of water, I buttoned the plastic parts back on and took a 15 mile drive. No issues. But . . . same day a cross town stop and go for 10 miles left me coasting through a VERY busy intersection. Engine reving to 3500 without shifting and a gearbox fault in the trouble window. Got to a safe spot and turned it off for 5 minutes and no warning lights and no trouble (I think). Drove another five miles to my destination without trouble and it sat for an hour. 45 minute drive home in easy traffic at 45 mph, no problem. Spent 30 minutes going up and down an empty 4 mile straight, hand shifting, sport mode and normal mode, no problems. icarsoft tells me code 1799. So did I bugger the CAN/TCM with some circuit killing water that dried?

 

Hi is code p1799 if so use this thread as a start as it is about the same problem https://www.jaguarforums.com/forum/s-type-s-type-r-supercharged-v8-x200-15/help-needed-intermittent-can-fault-p1799-p1797-108018/

 

I'm going to go back into the harness that runs down the passenger side of the block next to the SC cooler. As I was replacing the butchered up wire loom I snipped a black/green small gauge wire. I soldered it back together and heat shrinked the repair. Maybe the repair has failed. Not really sure if the wire is part of the CAN circuit anyway but never hurts to check. Also noticed that after I made a corner at speed the transmission searched for 2nd gear and reved up the engine. The initial fault that started this post happened after some hard stop and go. Maybe the fluid level in pan is not correct?

 

what is your milage. ZF recommend that you change the oil after 10 years or 60000 miles.

its quite expensive as you should use the correct type of oil and change the the filter which is built into the pan (replace oil pan)

After a lot of research by a member of a British forum it was found that there are not a lot of oils that meet the ZF specifications
ZF 6HP26 6-Speed Gearbox Oils.

on the smaller engined models you may get away with a lower spec oil but it is not recommended to try with an STR.

 

going to check the fluid level now. If it's low, I'm going to buy enough bottles of Mercon SP (recommended for the Lincoln Navigator with same ZF 6 spd) to change out the fluid. PO just did a change with new pan/filter and connector seal w/fluid kit, but recommened another fluid drain and fill as car has 243 KM on the clock.

 

If you didn't already, read up on the procedure as it is fairly exacting but ensures it doesn't end up under filled.

 

Well, got the car up on the stands and level and pulled fill plug (discovering in the mean time that the rear tranny mount rubber donut is the consistency of . . . well dried doo doo) thus making it easy to get to the plug with my allen wrench. Almost a quart of pretty dirty fluid came out (a bit over filled I'm guessing). watched this:


So with a very small amount of mileage on this fluid and it's nearly opaque color, I'm not sure were to go with this next. Leaving all that crappy fluid in the torque converter rankles a bit. Feels to me like I've got two problems: CAN/TCM circuit and that annoying 1st to 2nd gear bump/slip shift when at operating temp (in previous post I stated that first couple of cold shifts are fine), and yesterday's shift search and reving after a hard cornering, which by the way did not repeat during the rest of the drive.

 

Sounds like you did not follow the procedure so it will be underfilled.

 

The gearbox temp needs to be between 30 and 40 degrees Centigrade. (NOT OPERATING TEMP!!!)

bob

 

How dirty was the oil? Did you follow the video and run the engine so that the gearbox was up to temperature or the oil level will not be correct. As the gearbox has done 243000 perhaps it's is time to do another oil change or do you have the receipts which show that it was done fairly recently?

 

Oil was very dirty, like I said opaque, not clear and yellow/brown, but greyish and not letting light through and the PO (who was doing good work getting the car ready for me) had just put in a full kit, pan/filter, seal, gasket and fluid (Lifegaurd). Going to pick up the Mercon SP (anyone have the capacity?) and a laser temp gauge @ Harbor Frght. and change out this fluid and see what happens. I asked before and got an answer but I'll ask again and risk looking perverse. Is there any way to drain the torque converter?

 

Take it all apart. Not easy.

You can roughly do it via flush such as through the oil cooler lines.

 

There is a method to get all the oil out of the gearbox here in Europe it is called powerflush you can find a centre for you here in America http://www.bestwesterntransmission.com/contact-us.

In Britain we are not a 100% positive if that oil meets the specification given by ZF who had lifeguard 6 especially developed for the Zf6hp26. That is why I sent you that list of oils that we have found with the help of BMW forums to meet the specs. If the American cars use this gearbox as well then the oil should be ok but I don't know for sure.

 

You don't need such a machine but I expect it's easier with such.

Mercon SP seems fine. Several have used it over years and Ford also use it. Can't swear it's 100% OK but no problems seem to have surfaced.

 

"If the American cars use this gearbox as well then the oil should be ok but I don't know for sure."

Thanks for all the input guys. Powerflush seems to be available only in Colorado. I've read a few times on the forum that the Lincoln Navigator uses the same transmission as the Jaguar and Mercon SP as well. Guess I'll just run a few fills of the Mercon through it until it cleans up. Cheaper that a service at the dealer I suppose.

Can anyone picture and highlight the pin connector that could be the cause of my p1799. As I said I had cleaned the engine bay from on top only with just a spray bottle and a paint brush just to get off the light dirt and grease, using no pressure to speak of. I did disconnect some pin connectors that had crapped out loom and tape around them and recovered with new loom and tape, a least one had the lock release busted off . . . so if TCM is connected through one of these joints it would be nice to have an idea on its location.

 

According to P1799, it states its a CAN fault between your ABS module and TCM module. Did you have any other codes logged in the vehicle? Remember that these vehicles are on multiple networks, could be codes logged in ABS module as well.

 

No DTC codes for ABS alone, according to the icarsoft reader. I am still hoping this is an intermittent problem that will rectify once the "cleaning" I did drys, or I clean all the pin connectors with CRC as per the thread that Dat linked in this post earlier.

 

I would start by checking all those connections that you took apart do them one by one. As one of them seems to me that logically that one of them could the culprit.

 

Thanks Ducmon. I hope logic prevails as I check and clean those pin connectors. CRC makes an electric connection spray cleaner. Meanwhile back at the ranch. I've dropped the transmission pan and got about 4 qts US out of it. Not quite as dirty as I had first thought. With the 1 qt. I let out earlier, that makes five. So . . .most posts say that you can get up to 6 1/2 qts back in which leads me to believe it was low. Perhaps PO didn't do the temp. reading and thus underfilled it, (which maybe lead to the 1st to 2nd slip I had after that hard corner?). Anyway it sure didn't take as long and gush out like the Jag TV video. And remember when the fluid was cold (under operating temp after first start up), that 1st to 2nd shift was smooth, but once up to temp it slip/bumps.

 

Just take your time and be careful with the bolts when you do them up as they can break when you use to much toque.