V70 T6 2010 - engine overheting message 1-2min after start of the engine

mbinder · Post by **mbinder** » 28 Feb 2019, 00:32

Hi All,

I have an issue with my V70 T6 y2010, when I start the engine, outside temperature below 0, even -10°C, in one or two minutes it shows the message engine overheating slow down, followed by fail-safe mode, check engine starts blinking 2-3 injectors are disabled. When checking the engine temperature at the same time it is between 10-30°C, this happens when the car is left started for few minutes if I go immediately after a start like 20-30 sec there is no issue. if I stop the engine and start it again the message is cleared and everything works fine.

The same happens if I come home after driving 30km on the motorway, stop to open the gate, the message about overheating comes up, followed by safe-mode, engine temperature is around 90°C.

There is no fail code written, I was also by Volvo dealer they run diagnostic and did not find any issue.

Any idea is really welcome.

Thank you
Michal

Post by **precopster** » 28 Feb 2019, 06:16

Jimmy57 wrote this fix for me for a similar problem on a 2008 V70T6: I hope it helps you and worth a try. Changing fan controller would be next after this.

The fix on that car was to remove the strip fuse, 11A/44, and clean the contact points and put it back together. The diagnostic may be to trigger fan and do some internal shunt measurement in a fraction of a second and it sets that code. That could be why it does it with other modules since it is an issue on that car. That fuse is on the front of the upper layer. Not easy to get to so you have to unlatch the box and lift it. Undo the 10mm nut on the bus. There is a grey tab on inboard(engine side) of that upper layer to push and keep pushed aside, a grey tab in front center down in about 19mm down, and the black outer box has a tab that latches onto the box just aft of that strip fuse. Then you grab and pull straight up with pliers around the box. Once it lifts 4 or 5 mm it comes on out.

mbinder · Post by **mbinder** » 28 Feb 2019, 06:45

thank you, I will have a look, I actually have new fans including the control unit and since that, the issue occurs, what happened was that the fans were continually running on full speed, draining the battery to zero for all the time, immediately after connecting to the power, the Volvo dealer replaced the fans and control unit saying the control unit is faulty and it is delivered as one part.

Post by **jimmy57** » 28 Feb 2019, 11:26

That is odd. It is very unlikely that the engine could get the ECT sensor to 215C in two minutes. I wonder if there is a chafed wire or some other issue going on now.

Post by **precopster** » 01 Mar 2019, 12:00

The T6 I was working on also had the Engine Overheat message according to the auto electrician even though fans were coming on at correct speed.

I didn't see that message during my inpection.

Initially the same symptom as yours; fans coming on at full speed until controller was replaced. ECT was also replaced.

Carefully inspect wiring on that car.

mbinder · Post by **mbinder** » 06 Jul 2019, 06:45

Hi All,
I have not managed to get the right bottom of this, but it seems it was related to some wiring under the fusion box or between fusion box and the fans control unit as after changing oil in the gearbox the message never appeared again, for about a month, then was the car unfortunately destroyed during small fix of water pipe followed by crash during test drive.

thanks all for the answers.