Hi,

I am currently in discussion with the current owner of what i though would become my future car (Daimler super V8, 1998, 160Kkms, see introduction post). Unfortunately before I go and see the car (1000km away) the owner called me to say that a "transmission fault" error just popped up on the dashboard and the limp home mode kikked in (electrical limp mode, car blocked in 2nd gear).

He is in a remote location and does not have Jaguar dealer anywhere close, so he brought the car to the local garage. The mechanic scanned the ECM codes and get something related to solenoid (unfortunately he did not write down the code but I assume it was a P0753 or similar). Then he cleared the code and was surprised to find out that the car was driving just fine, passing all gears. The dashboard is still showing a "transmission fault" issue though.

I assume this is because there is still a code stored in the TCM that the generic scan tool cannot read nor erase.

What is not clear to me is whether the fault condition is still there or not. Assuming the origin of the fault has disappeared (which i doubt) or has been fixed (I know it has not for the time being) would the TCM code go away on its own? Would the TCM code be cleared at the same time or shortly after the ECM code is erased? Is there no other solution than go to a Jag dealer and have both ECM and TCM erased to be sure the fault has been repaired? And go back as many time as needed to the jag dealer if previous repair attempts fail to keep the ECM/TCM error free?

In the JTIS diagnostic procedure for code P0753 (tranmission for supercharged engine), I can see a procedure that tells to switch ignition on, then ignition off for 2mn, then ignition on again and start the car and rev to 1600+ RPM and check that codes have cleared. Is this procedure enough to clear ECM/ETM codes assuming proper repair has been made and erase "Transmission fault" message? Then why bother with the special Jaguar TCM scanner?

In the JTIS, I can see that the solenoid related faults trigger the limp home mode (blocked in second gear) on the second occurence of the fault (on 2 different driving cycles involving all 5 gear changes). Assuming the fault is steadily reproducible, is it enough I drove the car twice, passing all 5 gears each time, to bring it back to limp home mode?

Hope I have not been too long and this inspire you some comments.

Cheers,

Bruno

 

I am familiar with the ZF transmission in the normally aspirated XJ8. Is this car supercharged or not? The JTIS you quoted is supercharged and that car has a Mercedes transmission and so you have to be reading the correct information for your car.
If it has the ZF transmission, walk away form the deal. Transmission faults do not cure themselves or just go away.

 

Yes, this is the supercharged model with the Mercedes transmission.

 

Then the codes should appear through OBDII and you should be able to clear them with a scanner.

If not - try to lift the car and look at the transmission - the MB gearboxes always have a diagnostic cable.

 

The local car mechanic said indeed some code were visible with the OBDII and he was able to clear them, which has had the effect to get the car out of limp mode. But the "transmission fault" message is still showing on the dashboard.

Anyway, the current owner of the car has decided to drive the 100km that separate him from the next city and bring the car to the Jaguar dealer.

Let see if Jaguar can find something to fix or if they just reset the "transmission fault" message and let the car go.

I guess if I still decide to buy the car and this thing decides to come back one day, I am good to buy AutoEnginuity + Jag expansion if I pretend fixing this solenoid issue myself and be able to reset the "trans fault" message? None of the cheap code scanner will allow me do that right?

 

The end of the story: previous owner brought the car to Jaguar dealer who erased the remaining transmission codes with the factory scan tool. His test drive did not show any new occurence of the problem. I finally bought the car and drove 1200kms since then without any issue.

Last weekend I dropped down the right catalytic converter to get easier access to the 13 point transmission connector, unplugged it and found it was clean and dry like when it left factory 14 years ago. I also has a look at the intermediate connector (on top of the converter bell) and found no issue. I thought there was dirt but it seems some kind of electrical grease. Also checked the 2 connectors on the TCM: all clean.

Since I was under the hood, I also lifted the left cam cover to find out without too much surprise that I still had the original plastic tensioners, without any visual deffect though. Not Sure what I should do: let it as is, go for minor secondary upgrade, or go for the full distribution upgrade? I plan to keep this car on the long haul and possibly double the mileage on it (has 160k kms ~ 100kmiles today)

 

As you intend in keeping the car for the long haul...I would advise you attend to the tensioners and chains and slippers of both the the primary and secondary.
You should also inspect the water pump, thermostat (which should be replacd as a service item), thermostat tower.

160,000klm is around the time of replacement for both the serpentine belt and supercharger belt and their respective pulleys and tensioners.
Despite the previous owner, I would suggest flushing the oil system and new filter.
Use a high quality semi synthetic 5W40 or full synth if you wish
Flush the cooling system and new coolant.
Check all hose integrity as they are probably original.

The Mercedes box at least has a dip stick facility to check oil level and if it were me, I would be seeing about a complete flush and transmission oil replacement, considering the distance you are going to be covering.
The super charger oil should also be replaced at this distance.

The spark plugs should have been change by now....if not do it and check all the ignition wiring and the coils themselves
Some of these codes can be caused by a battery that is reaching the end of it's life.
If you intend replacing the battery don't go for a cheap 'open top' lead acid battery....they won't 'cut it'
By a good Varta 100 a/h 880CCA sealed Silver Calcium battery....these are man enough for the job and will last for years.
Mine is approaching it's 12th year of service....why, because I keep it on an automatic charger while not being used.

These are a damn fine car, especially the Super V8 with there extra equipment and greater attention to detail during assembly and will appreciate over time because of their rare state.
Apart from normal servicing and brake replacement (being fitted with the Brembo system) it is a relatively simple vehicle to keep maintained properly...at least it won't be used as a 'shopping trolley' like so many of our fine cars, which ends up ruining them and owners start whining and compaining about things going wrong.
I hope you get many satisfying klm out of your lovely steed...they are truly one of motoring's great achievements.

 

I decided to do the secondary chain tensioner upgrade. I used the simplified method (described somewhere else on this forum) consisting in lifting the exhaust camshaft. That was really easy and cheap (no special jaguar tooling necessary). I did have some small cracks starting to develop on the hidden side of the old plastic tensioners. Also I discovered I have a small crack on the left plastic cam covers, near the rear outer bolt. I fixed it with some epoxy glue but I have discovered I have another crack on the next bolt -> my next week end duty unless I decide to go for new cam cover.

Other things I did on the car already:
- right headlamp leveler motor replacement (electric motor dead)
- full load breather pipe replacement
- resoldered badly repaired wire harness in the front right wing (turn lights)
- resolder yellow wire in the steering column (togling button at the end of headlamp switch for trip/odo computer not functionning)
- got central rear mirror serviced (electrochromatic mirror replacement)
- replaced cut windshield washer hose at the base of the wiper arm.
- replaced burnt fuse under rear seats and found the power fold mirror function was working.
- replaced failing right mirror power fold case with a good used one
- replaced right mirror glass by original model with electrochromatic function
- replaced failing rear right door microswitch (bought complete used latch mechanism)
- replaced trunk lid microswitch
- glued trunk lid lights frames back into place.
- found after quite some time that the ? shape screw laying next to the battery had at least 2 purposes: pop out the wheel caps and immobilise the spare wheel in the trunk.
- rebuild all power-seats-switches-illumination/power-windows-switches-illumination/gearshift-console-illumination with LEDs. I used 12V-ready white LEDs which I painted yellow and on which I put back the blue cap provided on the original bulbs. The combination of white LED with yellow paint and blue cap is giving me the exact same green/blue color as original bulbs. This car has the separated electrical seats in the back so there are a lot of switches!
- fix a couple of bumps, removed a bit of rust, and repainted the bottom of the trunk (spare wheel and battery compartment)
- fixed front armrest cupholder (unproperly re-assembled after previous owner got front seats leather replaced).
- re-glued the center stop-light glass clips to the rear window
-replaced dead motorola phone battery and ordered a full size (credit card size) SIM card. Phone operator FREEMOBILE just lanched a 2€/month 1h/free subscription in France.
- replaced car battery. Found exact height for Jaguar XJ (19cm) instead of the 20cm I had on the car and was preventing the battery cover to sit properly.
- replaced broken silenc-bloc holder on the exhaust line (intermediate pipe to transmission cross beam (supercharged specific part number)
- Replaced broken side marker as well as missing jack hole plug
- Could not find lambswhool overrug at a decent price yet ( I need "sable" color, rear pieces are for a long wheel base, at least the 2 left pieces mandatory, I have the 2 right pieces).

Next on my to do list is the headliner...

and sure enough, no more worrying signs from the Transmission Control Module. Did I fix some hesitating contacts when unpluging all the transmission electrical harness?

Something I have got when battery is low is "ABS and traction control" error message. That clears itself after a while. I am wondering if this is normal of if this is the first signs of a failing ABS control module. I have read there are some solder joints that develop cracks inside this ABS module and need to be resoldered. I even got the error message once after changing for the new car battery (the car was left unused for 10 days).

 

I don't know why my signature is not showing. I did fill everything in my profile and added my car description in the garage. If someone can help.

 

Bruno,

Go to User CP button at the left of the black main menu banner. Select Settings & Options then Edit Signature to enter vehicle details.

You've been having a busy time with the Super V8. Good to hear the transmission fault has been fixed.

Graham

 

Thanks Graham,

should work now.

 

[quote=bballarin;538586]I decided to do the secondary chain tensioner upgrade. I used the simplified method (described somewhere else on this forum) consisting in lifting the exhaust camshaft. That was really easy and cheap (no special jaguar tooling necessary). I did have some small cracks starting to develop on the hidden side of the old plastic tensioners. Also I discovered I have a small crack on the left plastic cam covers, near the rear outer bolt. I fixed it with some epoxy glue but I have discovered I have another crack on the next bolt -> my next week end duty unless I decide to go for new cam cover....>>>>>>>

Hello Bruno....man! have you been a busy lad ;o))

Good to see you are working through a whole raft of 'issues'
You are going to end up with one fine car.
Normally these cars with the Mercedes trans are very reliable but like everything they eventually need attention.
90% of electronic glitches are caused by dirty connections or a failing battery.
It's extremely importan thast these cars have the correct battery that is on full charge.
Keep in touch and let us know how you are progressing ;o))

Cheers,
Xjay8

 

Hi xjay8

"90% of electronic glitches are caused by dirty connections"

That is very true. A few weeks ago I got my brother in law calling me hopeless because a 1986 porsche carrera was running very rough and he was suspecting the bosch ECM was going out. This is a very expensive piece. I was not too sure of the result but I told him to ship the ECM to me and i would open the ECM and heat all the printed circuit solderings (I have access to a soldering station with heat gun).

It took almost an hour to heat and melt the thousands components solderings on the 2 printed circuit board but a few days later, he call me back and said the porsche was running just fine with this treatment.

 

....>>>>> It took almost an hour to heat and melt the thousands components solderings on the 2 printed circuit board but a few days later, he call me back and said the porsche for running just fine with this treatment.[/quote].....>>>>>

Greetings Juan,

I had this very same thing done to the ECU on my old '82 Rover 3500SE.
When i received it back and installed it using di-electric grease, cleaned up all the connections and earth points... it was transformed, like a new car ))

I always try to look for the simple problems first and 9 out of 10 times it works.
Modern electronics are quite reliable and it is usually eartings and connectors that are the first port of call for a problem.
Considering that our cars are reaching nearly 15 years old, one has to be extra dilligent in tracking down 'problems'.....we are all getting older ;o))