We have a 59 plate 1.2 Lounge, owned from new with under 11K miles with a Dualogic gearbox and the "Transmission warning" light has kicked in again and locked out 4th and 5th gears - is this a common problem ?

Took it to a local specialist who recommended swapping the brake light switch (which has already been done) and said other than that, it would need to go to a dealer and refer to Fiat.

The problem is intermittent, sometimes it works fine for 5 miles or more then kicks in. It has done it a few times over the years - normally when returning from holiday when it hasn't been used for a while - but normally goes away after a few days.

I have tried replacing the battery, running an additional earth strap from the battery to the front upper mounting point (and removing it again), wrapping the rear light wiring in rubber amalgamating tape, replaced the high level rear brake light after one of the sections stopped working, wired an additional earth to the rear lights etc - now running out of ideas!

Our driveway is steep so the car normally sits with it's rear pointing in the air and when I removed the rear clusters, the paintwork behind them was filthy.

Any further ideas ? Can anyone suggest a good specialist for Dualogic cars ?

Thanks

Gavin

You need to get the fault code off of the gearbox ECU which will give you some more ideas. When sitting on the drive bum in the air, pour water down the windscreen into the scuttle with bonnet open and check its not running all over the gearbox electrics, or behind the splash guard cover on the front of the gearbox.

I assum it won't select the mentioned gears in either manual or auto mode?

My OH's previous 1.2 Pop with dualogic, would drop into Neutral whilst driving. On diagnosis the Gearbox ECU required replacing. All done under 3rd Year warranty, after which no issues.

I'm not seeing the connection between the back end of the car being dirty and the 4th-5th gears being disallowed?

Have you tried an end-of-line calibration with MultiECUScan? If there is a fault with the gear selector position potentiometers, the calibration procedure will show it up. If the calibration has drifted a little, the procedure will correct it.

-Alex

Thanks for the replies guys - certainly some food for thought there.

We have now swapped where we park our two cars so the Fiat is on level ground to see if this makes any difference. I have also ordered some Holts Damp Start Autoplast to spray liberally anywhere electrical under the bonnet.

I do have the MultiECUScan software/cables and historically the errors are normally relating to the brake pedal switch which is obviously connected to the brake lights at the back of the car. I have replaced this a couple of times so the wiring seems to be the most logical cause.

The Fiat specialist we took it to connected it to their factory diagnostics and they mentioned the gearbox ECU as a possible cause but I am seeing no errors for this with the MultiECUScan software ?

I'll monitor it over the next couple of weeks and see if it improves and update the thread.

Thanks

Gavin

gavinp said:

normally relating to the brake pedal switch which is obviously connected to the brake lights at the back of the car.

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No its not, brake light switch only connected to the body computer, its the body computer that then operates the rear brake lights.

Most Easterly Pandas said:

No its not, brake light switch only connected to the body computer, its the body computer that then operates the rear brake lights.

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I stand corrected - thanks

Will take on board all the suggestions and see if the situation improves - it is a shame as the other half loves the car but the gearbox is souring the whole experience for me.

Thanks

Gavin