@TonyN-transmission/overdrive issues

[angelonawire]

Tony you mention a transmission ecu, is this the same for the 3.0l or is it a combined engine trans ECU.

I have recently lost overdrive lockup,(2 weeks ago) it only ever gets to 3rd gear and is revving higher than normal before it changes up, when it does change up it does so with a fair kick rather than a smooth change.

I have been towing a fair bit recently and noticed the engine temp rising (not into the red), i removed the stat, water is flowing well through radiator, so I am guessing that it is the trans fluid causing the temp rise.

now if i am driving over 50mph without a trailer, as it is only getting up to 3rd it starts to rise in temp as the revs are sitting around 3200 to achieve 50 mph

i had a sniff of the fluid and it did smell a little burnt and was pretty black/brown in colour, so I flushed through 15 litres to clean it out with 5 mile drives between each 5 litres. this didnt help

I then bought a "thoroughly tested and working" ECU off fleabay, changed that out and still no joy.

Any thoughts, I know this is a common fault but there doesnt appear to be an easy solution

the only wiring that appears a little dodgy, are the two large plugs up high on the near side of the trans box, they were taped together, and I soldered them up about 6 months ago, what are they and could this give this fault?

oh and there is nothing abnormal with dash ECT and O/D dash lights

thanks

[TonyN]

Could be the solenoid for O/D, or the ECU. You normally get the O/D light flashing when its the solenoid, but often no light if its the ECU.

There is no seperate gearbox ECU on the 3.0.

I'd try disconnecting the 3 pin plug on the N/S of the gearbox, this disconnects all the electric control to the box.

When you drive it you'll have to select all gears with the stick, but you should get L 2 and O/D (no 3rd, this is only electrically selected) this proves the gearbox is mechanically correct and O/D works.

If you've done the ECU and trust it, I'd change the solenoid next and see what happens.

[angelonawire]

o/d solenoid

Where would I find the O/D solenoid?

[TonyN]

Inside the gearbox.



You have to take the front prop off, and remove the gearbox sump and oil strainer, then you can see the solenoids.

You'll have to look up online which one it is, I can't remember, there are 3.

[angelonawire]

ECU Doctor

Well, I thought it best to have my ECU checked out, so I posted off to the ECU Doctor in Plymouth. It turns out that 4 x resistors had to be replaced along with the main CPU, followed by a full reload of the software. £260 fix.

Any thoughts on what may have caused that??, there was not any signs of water ingress when I had a look inside.
I'm offshore until Tuesday, hopefully I'll plug it in when I get home and all will be well!!

[angelonawire]

ECU Doctor Rocks!!!

Happy days, fitted my refurbished ECU this morning and took the surf for a spin......and I now have overdrive again!!!,the box is working properly as before with all gears changing at the right time.

Thanks ECU doctor!



I'm a happy boy