MAN 1100 expansion tank code

Probably a very common sensor failure on the tank. Swap the sensors from side to side to verify. I'd replace the caps too if that hasn't been done.

If you search for a thread by CSkipR he had current pricing on the sensor.

MAN recommends changing both expansion tank caps every 2 years, make sure to change them with OEM Man ones. I would do this, THEN on the middle of the expansion tank is a shrader valve, pump it up to 16 psi. Sometimes if you open the cap a lot, and don't pump up the shrader valve, it will throw a code, it's rare, but I've seen it. Run the vessel and see if you're still getting the code. Also what PSI is it saying for the expansion tank, should be on the display, they usually show around 4 psi at idle and 12-13 psi at cruise.

If you are IT IS the sensor, located in the lower front corner on the bottom of the expansion tank on the ones I run. If you open the cap, then close it to bleed off the pressure, you can get away with changing this sensor if you have the other one ready to go, you can change it without dropping the coolant and only spill a few ounces of coolant. Sensors are the most common issue on the 1100 common rails, other than that and the hour meter/alarm monitoring boards, they
ve been great motors in my experience.

Having been through this I agree with CapJ post above. At zero PSI cold it still shouldn't throw and error but that is a way to diagnose. In three season I've had two sensors fail. One was an air plenum and the other was this expansion tank.
This is one of those things you need to follow the simple stuff first which is what has been outlined above. High chance it's just the sensor and replace the caps just for PM. That said, watch the coolant level. Good luck.

Hello

Like all membre tell you if you open or if you cap are old where coolant if hot you get alarm.
If you coolant if dirty that also can bloc the hole from your sensor pressure.
Any way look like you in St Martin, I'm next to you in St Barth and have all in stock cap, sensor .... and diagnostic tool too so just email me email address removed

hugues

Wow, that is a great offer.

you know I'm living on yacht since 10 years helping other owner I'm doing that since 20 years sale on expansion tank cap I really don't care not going to change my life ...
I love MAN and did many factory training

Hugues