[SplaT-46]

Hello, checked my error codes today as my OBDII lead arrived and i have a recurring error code of p3240 (dealer specific). Google says this code means (map cooling thermostat control circuit open circuit) few explanations have mentioned replacing sensors or replacing thermostat as these are electronic and wear? Is anyone familiar with this issue, or happen to know if these thermostats are electronic and where exactly it is located. Help much appreciated.

 

[TheEnd]

The are electronic themostats on BMWs, although you may not notice any differences with it failing.

It works by having a slightly higher than normal opening temperature, which still works the same way as regular ones, but it also has a heating coil, which means the ECU can open the thermostat earlier and keep the engine slightly cooler.

They are pretty problematic, but they have little if any affect on the running of the car, and I'd give a rough estimate of about half of them in the UK aren't working judging by how often they turn up as fault codes.

 

[SplaT-46]

So are these mechanical/temperature operated just with the aid of an electronic coil? Very stupid question but where exactly is the thermostat, i cant find any good pics.

 

[TheEnd]

http://realoem.com/bmw/showparts.do?model=AY72&mospid=47632&btnr=11_3192&hg=11&fg=35

Part 2 and the seal O ring 3 should come as the 'stat, inside the housing, part 4.

The thing that stands out to me is that doesn't immediately stand out as an electronic thermostat, BMW usually have a little warning triangle pointing to any electrical components in their parts catalogues.

Try it with you own chassis number, the last 7 digits of the VIN number you can see through the dash.
Navigate to the same spot- ENGINE>ENGINE COOLING>WATERPUMP-THERMOSTAT and see if you have something similar

 

[mojojojo]

The thermostat is on the bottom left of the engine, if you follow the hose from the bottom of the radiator to the engine you'll find it see pic. Check the plug is connected properly and for any brakes in the cable. I had the same code (turned out to be a blown fuse but that threw other codes up as well).

 

[SplaT-46]

Cheers, ye it is the same part, will check out mine tommorow in better light, checked out some on ebay and they are listed as electronic, hopefully this is the cause of my code.

 

[SplaT-46]

Thanks mojojojo, will definately check fuses and plugs! at least i can save money on code reading now.