My mondeo with 153k miles is suddenly very poorly and I suspect its going to cost a fortune to fix.

This has been happening from wednesday, after I let my brother borrow it following the sale of my old vRS.

Symptoms

When in D, the car appears to be fine. Except in first gear it revs to the red line before changing gear, not to second as you would think but to third. The gearbox seems to be missing second gear, moving the selector to 2 from stationery an pulling away there is forward drive, but in what gear I am unsure. If you select 2 when in motion at say 30MPH, you get no drive and the engine revs as if its in neutral. The gearbox fault light flashes sometimes, but not all the time. Sometimes it does manage to get second, usually on downshifts from third.

The transmission is computerised so has some sensors, in that it has a sport mode and normal mode. The computer is used to determin what gear the car should be in and sends signals to various solenoids to change the gears.

So I guess I am looking for ideas and likely location of sensors or wireing problems.

I had a VW auto box do something like this, and that was electronically controlled. It was something to do with a dodgy temp sensor, and that cured it.

check the oil , is level ok ? what colour is the oil ? is it brown ? , does oil smell burnt ? if so auto box probably u/s , auto box replacement required , i think the price has gone down as well but still over £1k , you maybe lucky and its only a sensor fault but don't count on it

a 10 year old mondeo with 153K on the clock? bin it and buy another for 10p mate

we had one at work the other day , the customer wanted it stripping for repair but when it was unrepairable he had to pay for the stripping and the new gearbox , it was expensive !

if it has to be another mondeo manny then there are plenty on autotrader under £500 even a 2.5V6 with full leather

Checked the fluid levels, and the colour/smell. Its all fine, no nasty smell and the level is correct.

I suspect the issue is with the electronics, maybe the shift solenoids (are they servicable). Does anyone know where the electrical connection to the main transmission is, its raining and I dont want to get to wet.

I found this webpage that shows what signals are needed to get the gears to shift appropriately.

http://www.atraonline.com/manuals/general/tetdv/tetdv-c4j.htm

I have updated the first post with my findings after driving the car today.

When in D, the car appears to be fine. Except in first gear it revs to the red line before changing gear, not to second as you would think but to third. The gearbox seems to be missing second gear, moving the selector to 2 from stationery an pulling away there is forward drive, but in what gear I am unsure. If you select 2 when in motion at say 30MPH, you get no drive and the engine revs as if its in neutral. The gearbox fault light flashes sometimes, but not all the time. Sometimes it does manage to get second, usually on downshifts from third. 4th gear (overdrive) is fine, I confirmed this by pressing the OD off button at 70mph and the revs increased as 3rd gear was selected.

From reading on the web, whats happening is the ecu is sending the signal to the gearbox for 2nd. The ecu then thinks the car is now in 2nd but in reality its still stuck in 1st hence the high revs. 3rd is only selected at the appropriate road speed for 3rd gear unless you lift completely off the throttle then 3rd engages instantly as it always has.

could be the module on the top of the gearbox , iirc it tells the PCM what gear is selected , i think i changed one a while back , sorry can't remember how much it was