Water in gearbox ecu.

[zetecor]

Hi garage have told me after (after seven weeks and a trans rebuild) that they think my 'trans fail prog' is being caused by water in the trans ecu. How can water get in there, where is it? I have to top my coolant up every six weeks but cannot find any leaks could coolant find its way there? they are fitting a used part next week.

many thanks.

[amacman]

The transmission and engine ECU are in a container located on the left side of the engine bay at the bulkhead .The container lid is secured by a few screws .It is positioned where the brake booster and master cylinder would be on a left hand drive model .
BMW TIS shows it .BMW TIS - 12 14 550 Replacing control unit (Digital Motor Electronics) (M62, M54)
The containers can allow water ingress causing damage .Coolant will not get in there . The coolant leak needs proper investigation as there are many possibilities with the most difficult to find being the valley pan and pipes at the rear of the engine .
I saw your post on another thread about BBA- Reman demanding money with menaces , what is that all about , have they done a full refurb on your transmission . Did you sign a work order authorising the work . The lack of detail makes it sound disturbing .

[zetecor]

Hi,
thanks for that at least I can rule out coolant ingress and will need to look for rainwater
problems. No haven't used BBA-REMAN, were just looking for feedback on them after a gearbox specialist reconditioned my gearbox but failed to solve 'trans fail prog' and then suspected gearbox ecu failure.
When they removed the gearbox ecu they have told me it has been affected by water. So going to fit used one.

[civdiv99]

If you got water in there, then I am impressed. Been blasting through pond-like puddles at 90 per?

[swissfrank]

Originally Posted by zetecor

Hi garage have told me after (after seven weeks and a trans rebuild) that they think my 'trans fail prog' is being caused by water in the trans ecu. How can water get in there, where is it? I have to top my coolant up every six weeks but cannot find any leaks could coolant find its way there? they are fitting a used part next week.

many thanks.

Not to sound rude, but I think it is time for a second opinion. However it is possible (but not likely) for water to pool at the connector, by pulling the connectors off and inspecting carefully for water damage or corrosion would show if this is the case or not.

[zetecor]

Hi, they have told me that there was corrosion in there due to water, they are fitting replacement used one this week, fingers crossed.

[BigBazzarati]

Hi. For the record, I have a 3.0i which regularly sucks coolant into the middle socket on the ECU. You can tell it's coolant cos it's blue and tastes of Glycol. Everything else is dry and it's an easy process to clean up but I'm concerned that one of the pins on the ECU will soon break due to the corrosion occurring in there. Have recently covered everything in WD40 for protection whilst I work out my next move. No idea how the coolant is entering the loom but it's presumably osmosis or static draw that's pulling it in there.

[zetecor]

Mine got fixed with the replacement

[Clavurion]

Originally Posted by BigBazzarati

Hi. For the record, I have a 3.0i which regularly sucks coolant into the middle socket on the ECU. You can tell it's coolant cos it's blue and tastes of Glycol. Everything else is dry and it's an easy process to clean up but I'm concerned that one of the pins on the ECU will soon break due to the corrosion occurring in there. Have recently covered everything in WD40 for protection whilst I work out my next move. No idea how the coolant is entering the loom but it's presumably osmosis or static draw that's pulling it in there.

Most likely cause is the connector on thermostat housing.

https://www.newtis.info/tisv2/a/en/e...0i-sav/V3OzlYg

[BigBazzarati]

Any idea how the water was getting into the old one?