Electrics playing silly beggers

[J44EAG]

Hello Brian,

There are two different throttle bodies for the V6 and V8. They are very similar so it pays to know the difference. The V6 unit has coolant inlet and outlet pipes inbuilt to the throttle body. They provide frost protection around the throttle plate which might under exceptionally cold conditions seize and freeze.

The V8 unit does not have those pipes as they are built onto the double banana bunch type inlet manifold. In other respects both V6 and V8 throttles are effectively identical visually but perhaps not internally. I suspect the motor, gears, throttle plate and throttle plate position pot are the same but the TAC module might be differently programmed.

The TAC circuit module sealed in a flat ali box about the size of a box of Swan Vestas is matched at production stage and neither unit can be brought separately. The only re usable part possibly is the throttle pot which is the only part that is removable. So if a problem with a motor or TAC module occurs then the only options are a repair from BBA Reman or direct replacement, new or used.

What ever model of petrol model S-type you own, it is essential to obtain the identical replacement part number. This can be found inconveniently placed on a sticker on the underside of the unit. Do not clean muck off the label with thinners. The ink on the label is very unstable. Just wipe off with a cloth. The part number is likely to start XR8.......

If buying new or from a breaker such as Eurojag, then best to give them the LAST alpha numeric figures from you car Vin Number ie M33066.

I understand that throttle pedal units are universal across the range but best to check with your part supplier. These units used to fail regularly but not so much of that issue heard in recent times.

Interesting information regarding electronic and IT history, Brian. Thanks for that.

Mike

[Martec]

Decided to have a play to find out which part of the drivers side rear door lock isn't working as a friend has offered me a lock from his spares car (same age and spec as ours).

Door and boot side trim panels off (whistle and they fall off), carefully removed the Rear Electronic Control Module and disconnected plugs CA 103 and CA 101 and using the electrical wiring diagrams for wire colours and pin numbers tested the loom from lock to RECM, full continuity, bugger it would have been easier to repair a broken wire.

So I'm trying to work out how to get the door lock out, only held in by 4 bolts, not looking forward to that job.

Decided to have a look at the heater valve as I now have 2 splashproof fuse holders and some 1 amp and 1.6 amp fuses. finally got my fingers on the electrical plug and removed it (battery still disconnected) and using some really long screw drivers (the boss always brings me presents of tools from ALDI) I managed to get contact with the 3 pins of the valve.

Between LH and centre pin 15.6 ohms
Between RH and centre pin 15.6 ohms

The centre pin is the 10amp fused supply, from these resistance readings and maximum alternator output of 14.3 volts the maximum ampage is 0.9 amps, so the solenoid coils are OK.............for now. Then it got really cold and started snowing so I gave up and the fuse holders are not fitted.

Brian

[Roger]

I am hoping someone is going to be able to help me / provide advice and this thread seems to offer the best opportunity.

About 15 months ago my 2004 STR developed an annoying problem displaying multiple warning messages simultaneously - Parking Brake Failure, Engine Management Fault, DSC, Cruse Control whereupon the engine would effectively shut down with not even enough power to move you down the road.

Having come to a halt if you removed the key and then restarted it would reset and you would be good for 20 or 30 more miles.

I Spent a small fortune trying to resolve with auto electricians and garages but the most frustrating thing was that nothing seemed to work for more than a month or so. The battery was changed, various ECU's and then in the last four months the throttle body followed by the accelerator peddle assembly.

That appeared to resolve the issue but shortly after the CATS suspension started playing up. I have had both the CATS sensors changed and all was well for six months but then the fault reoccurred a week ago.

The car is due to go in on 25th to hopefully have that fixed however this morning (16th March) when I started her the multiple faults mentioned above were once again being displayed and she would not do more than tickover. This time however removing the key and restarting has no effect.

Has anyone else experienced anything like this? I have heard that replacing the wiring loom that runs behind the front bumper may resolve but has anyone tried that and had success? Its a lovely car but I am getting to the end of my tether - I need something reliable.

All advice and recommendations appreciated

[J44EAG]

I`ve found that multiple faults stored in a pile in the power train module can cause a big issue. Disconnect the battery for 20 minutes, rest the clock and radio code and see if that helps in the short term as a get you going measure.

As you have reoccurring issues, maybe a trip to a good independent Jaguar garage would be well worth doing.

Dave Marks covered similar issues at the Seminar yesterday. Why not drop him a mail?

Suggest you continue to watch this thread as others may be able to help.

Mike

[Martec]

Hi Mike,

Nice to see you and Oldtimer yesterday at Castle Bromwich, what an excellent lecture, the organisation was as good as expected but was blown away by David Marks depth of knowledge, no question too difficult.

I learnt a lot and in particular the reason for 'B camshaft retarded/advanced'. In rubbish weather to and from Brum the car behaved very well, just listening to the wipers click and bang means I have good reason to play infront of the scuttle, but it was a comfortable relaxing journey all the same.

How did you get on with your leaking expansion tank?

Nice to meet you in person,

Brian

PS no sign of amber alarms, maybe putting the accelerator pedal ontop of the boiler for a night had the desired effect???...........for now.

To the guy with a misbehaving STR have they tried disconnecting and cleaning every earth and positive terminal, plus pulling and refitting every fuse and relay twice, as I found a lot of corrosion in various places?

[J44EAG]

Hi Guys,

Yes, the Seminar was a good one. Dave is a top man.

Most interesting about the accelerator pedal. Moisture can build up on the potentiometer on the unit and cause big problems. Two bolts securing it to the car. Take it off and put it in a warm place overnight then refit.

Great to meet Phil again and also Brian for the first time.

Nasty journey back this morning. Heavy snow blizzard from Birmingham down to below Oxford. Very dangerous conditions.

The header tank on J44 has developed a leak. Made it back with one stop to check the level but no top up needed. 42k miles use on this tank before the problem started again. The problem with the early cars is that the tank sits directly over the offside exhaust down pipe. This fries the polypropylene tank and the material "dries out" over a period of time and splits develop. Later cars have the tank moved to the front of the car, but even that hasn`t cured issues. On those the overflow pipe falls off due to fatigue!

Mike

[oldtimer]

Hi Mike and Martec,
I had to have a chuckel yeaterday,as I walked into the reception area I saw Mike just about to launch into a large Bacon Butty and I thought that bloke don't need a Sat Nav he really did follow the scent, Great to see you again Mike, pity there was not time for more of a chat.And Brian great to meet you too. Nice to put a face to a name.

Glad to hear that you both got home OK. I left at 17.00 and arrived home at 18.10. Seventy nine miles each way. Did'nt realise you were night stopping there Mike, so you caught that snow at Oxford, I live about a mile from Junction 8a so was surprised to see the car covered in snow this morning. Unlike your working car, mine is a cossetted toy kept in the warm, so having spent an age servicing and polishing underneath then to get it covered in salt on the way there, chucking it down with rain on the way home and covered with snow this morning I'm well miffed.

As for the day, Very good but must be difficult to pitch at the correct level to suit the various skill levels and needs. To cover all that ground within a given period needs to gallop on a bit and have to say that I would have liked to linger at one or two hurdles but I'm sure I'll make that up in due course.

Thanks to all those involved in arrangeing and running the day especially the Bacon Butty makers

Regards Oldtimer