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[JamesV6CDX]

Hi Folks, hope everyone is well. Just a quick query if I may please.

I am almost certain I have missed something really stupid, and I've not investigated in any great detail due to running out of time, and having to go on a short notice trip abroad, today. It's one of those things that I decided to walk away from, because if I look at it with a fresh head, I'll probably spot the problem straight away!

But, I won't get chance to look before the weekend, so I thought I'd instigate a discussion in the meantime, which may give me some ideas.

Background (you'll see in a moment why this is relevent) - in September I bought a 2.6 (2002 model) unseen from Arsebook marketplace. Cheap enough that I didn't care if it blew up on the way home. 98k miles, some faded paint and a dent in a rear door, but otherwise excellent condition.

The first 60 miles of the drive home were uneventful. I noticed that the 1-2 gearchange was a bit more pronounced than the others (although not rough) but nothing else stood out. After then, the battery charging light started to illuminate - first, dimly, but got brighter and brighter. Then, the dash lit up like a Christmas tree - ABS, TC, Engine lights, I can't recall exactly which ones, but it was like blackpool illuminations.

The engine kept running, though, so I ran the gauntlet and parked up in a safe place about 10 miles from home.

The next day, I fitted a fresh battery. It started up, but the charging light was still firmly on. A multimeter across the battery showed it was not charging at all. Whilst I don't believe in co-incidences, it was fine for the first 60 miles, so I can only assume the alternator threw in the towel half way home. I also noticed some small brown deposits in the header tank, which were definitely oil contamination, so it looked like the oil cooler was in the very early stages of failing.


I took it off the road at this point and took it to bits to replace cambelt kit, oil cooler kit, water pump, aux belt and tensioner, new alternator, radiator, thermostat, HBV, rocker cover gaskets, spark plugs, oil and filter. I also changed the header tank because the old one was manky and wouldn't clean very well. I disconnected all of the engine loom to do the work, apart from the connections under the car (gearbox and lambdas).

Yesterday I finally got it all finished. The engine runs very sweetly indeed and I'm pleased - but there is a small problem.

I noticed the engine light (with the spanner) and the TC lights were illuminated. A stop and restart, and they soon came back. I then noticed that there were NO lights at all, illuminated on the gear selector area. For example, if it's in park, there would be an orange light next to P. There is nothing at all there. Sport and winter mode don't work, so it appears the Transmission is in limp mode (which it wasn't before).

Interestingly, the temperature gauge on the dahsboard also isn't working, and I am certain the spade connector is correctly home.

Obviously, I need to read the codes / see what can be seen on live data, but I didn't have time to configure the laptop last night.

Things I have checked:

Following plugs, all securely home (reseated to be sure):

Selector switch
Both plugs to the gearbox, the square one in the front sump, and round one to the rear.
Speed sensor at rear of gearbox.
All lambdas, in correct connectors.
(none of the above was disturbed during the work).

I can also confirm the following connectors are firmly home and correctly connected:

Crank Sensor
Cam Sensor
Both Coil Packs
Both Knock Sensors
CTS
Carbon Valve
Fuel Injectors
Throttle Body DBW connector
MAF
Both Rams
Auxialiary coolant pumps
All radiator sensors

The three round connectors by the battery were my prime suspect, I have taken apart, double and triple checked them. They are clean, and securely home, all with a satisfying click.

I've also checked F6, (80 amp TCM fuse in the engine bay) which is intact.

The body earths under the battery tray - present and correct (and tight)

I have also checked that the battery terminals are secure, and that all of the smaller cables that connect to them, are correctly affixed (I compared it to my 3.2, they are all there, and correctly home).

It's almost as if the TCM is completely dead / doesn't have power.

I will plug in the poor mans Tech2 and see what it's telling me if anything, but I would be grateful for any ideas in the meantime

[JamesV6CDX]

I should have also said, X85 and X86 are also fully home (both engine ECU plugs), as are the cable from the ECU box to the battery terminal...

[Doctor Gollum]

The connection to the dash temp sensor is a 3" pigtail. Is tother end home?

The looms were starting to get brittle ten years ago... So don't dismiss a wider loom issue.

Are all the engine earths secure and clean?

Also, ecu plugs in the correct place?

[Marks DTM Calib]

Read the wiring diagram, you will note that the selector switch setup is actually pretty stand alone and receives power and ground independently of the TCM. It simply outputs a 4 bit code for gear position. The position indicators are also standalone and tap into the same 4 bit code, from memory they are switched off fuse 9.

[Doctor Gollum]

Any evidence water in the front footwells? Check the primary ugs behind the kick panels...

Looking for evidence of moisture/corrosion on the plugs and under the carpets. 

[JamesV6CDX]

Thanks all. Will report back after the weekend

[JamesV6CDX]

Footwells / TCM dry as a bone.

There is a P0705 code which means selector switch issue (or wiring to it)

Can talk to all ECUs.

Live data from TCM shows “error” for selected gear. Live data can detect if sports / winter buttons are pressed.

Fuses (including 9) are all intact.

Known good selector switch tried just in case. No difference, so refitted old one.

Engine earths all checked and three round plugs by battery checked and reseated again.

I think it’s got to be a break in the loom?

Does anyone have a wiring diagram please? I might be being thick but I can’t find a link on my phone.

Thanks

[JamesV6CDX]

Car won’t attempt to start, outside of P and N. So it does seem to have some vague idea where the selector switch is …

[JamesV6CDX]

All sorted.

The car had some electrical gremlins when I drove it home in September, and the loom doesn’t look the best.

I robbed the loom off my 3.2 project this afternoon and fitted it to the 2.6.

Now works a treat - no fault codes and drives absolutely lovely. Up and down the box with no problems at all - the pronounced 1-2 gear change has also disappeared.

Jobs a good’un  

[STEMO]

All sorted.

The car had some electrical gremlins when I drove it home in September, and the loom doesn’t look the best.

I robbed the loom off my 3.2 project this afternoon and fitted it to the 2.6.

Now works a treat - no fault codes and drives absolutely lovely. Up and down the box with no problems at all - the pronounced 1-2 gear change has also disappeared.

Jobs a good’un

Well done, James 

[JamesV6CDX]

Cheers mate. I had no motivation at all over winter, but now the sun is out it was rude not to get this on the road! MOT next