Rex Drive Train error; High coolant temperature

[Lykke]

As many others we have been struggling with the standard rex "drive train error - have it checked by serivce" fault, it seems to pop up after +30min rexing at high speed.

Now warranty is running out, so I intend to insist the dealer fix the problem. We have had the SW updated to I001-16-03-504 and the high voltage cable replaced, and I managed to run through a full tank of gas without getting the error. I also ran my OBD-2 reader during the test and noticed the coolant temperature ended up being very high; 104oC (219oF).

Is this normal?? Sure never saw anything like that on our old ICE cars :-/

 

[jadnashuanh]

The reason there's a pressure cap on the coolant systems of vehicles is to raise the boiling point. Given the location of the engine, it doesn't sound out of range to me.

 

[psquare]

As many others we have been struggling with the standard rex "drive train error - have it checked by serivce" fault, it seems to pop up after +30min rexing at high speed.

Never heard of this problem, but what do you consider "rexing at high speed"?

 

[janner]

The rpm of the ReX and the car are not related. Unless the battery State of Charge is very low then above 56mph the ReX will run at 3600rpm and produce about 20kW (18.8kWe). If the SOC drops to below 2.5% then the ReX will run up to 4300rpm and deliver 23.3kWe or in Europe 4800rpm and 25.5kWe ( new 94Ah range will run at 5000rpm and produce 26.5kWe).

 

[janner]

The ReX engine coolant thermostat starts to open at 85 deg C and is fully open at 95 deg C. Above 85degC the engine coolant circuit passes heat to the electronics and motor cooling circuit which then includes the front mounted radiator.
There is also an engine compt cooling fan.

 

[Lykke]

As many others we have been struggling with the standard rex "drive train error - have it checked by serivce" fault, it seems to pop up after +30min rexing at high speed.

Never heard of this problem, but what do you consider "rexing at high speed"?

I probably should have written "high load", i.e. when the rex is struggling to keep up.

After I did the post, I have become unsure if the high coolant temperature only appear when the rex is turnes off again. Guess that stopping the rex may also turn off the coolant pump? Will have a closer look next time I go rex'ing.

 

[janner]

the coolant pump is electrically driven an so doesn't need the engine to be running.

 

[Lykke]

Did a longer trip, 400km, and burned 3 tanks of petrol without getting the fault again. Maybe the new SW, I001-16-03-504, actually did do something

High coolant temperature only appear when the rex is stopped, this time it got up to 114°C, I assume it's because the electric coolant pump is indeed turned off when the Rex is powered off.

 

[TOEd]

On our 2015 the fan at the rear of the car continues to blow hot air down towards the ground after the car is shut off. It does this for a minute or two particularly after a highway run. Not sure if the coolant pump is running but my guess is that it is. Never seen that error after 3334 km of REx operation.