Heater Not Working

[yogi3]

Hello. Interesting ideas here for the intermittent heating issue. Going to share an update from yesterday. I’m not the OP but my experience might help others too. My 2019 i3s REX doesn’t have a heat pump, still trying to diagnose. Dealer claimed my intermittent heat was completely fixed. They did fix the left/right hot/cold issue as related to error code 801186, and now I have equal and full heat through all the vents. Was previously getting weak air and only heat through left 2 vents, and cold air through right 2 vents. ONLY when the heat worked occasionally. Sometimes cold air only for all vents.

However, was sitting in the car with the tech, who was demonstrating the heat flowing successfully. I turned the car off, stepped out, turned it back on, and zero heat would come from the vents. Cold air at full blast with the dial set to 84° F. He was in shock. I’ve left the car with them to continue to diagnose. If anyone has had this issue with a late model i3 and had it fixed, please share what the fix was. Again I don’t have the heat pump. I’ve seen it said it could be the fuse only in the heating element, while others had the entire heating element replaced. I don’t have any error codes for the heating element specifically. It was just that left/right mixed air issue.

 

[mojo]

I recent poster on the UK i3 FB group found that his problem was due to a fault in the cable that carries the LINbus connection to the BDC and HVAC controllers. I think you should expect to get a very specific LINbus fault code in that case though.

 

[yogi3]

I recent poster on the UK i3 FB group found that his problem was due to a fault in the cable that carries the LINbus connection to the BDC and HVAC controllers. I think you should expect to get a very specific LINbus fault code in that case though.

I recent poster on the UK i3 FB group found that his problem was due to a fault in the cable that carries the LINbus connection to the BDC and HVAC controllers. I think you should expect to get a very specific LINbus fault code in that case though.

Thank you, I’ll be on the lookout for the Linbus error code, though I haven’t seen anything like that yet. I won’t be taking my car from the dealer till they can fix it.

I recent poster on the UK i3 FB group found that his problem was due to a fault in the cable that carries the LINbus connection to the BDC and HVAC controllers. I think you should expect to get a very specific LINbus fault code in that case though.

 

[AUTOMAN]

After some research on this heater I would strongly recommend checking the temperature sensor which is located on the top of the unit. These are available at a low cost and could result in a cost efficient repair in comparison to replacing the whole unit . Just a thought.

 

[eNate]

...was sitting in the car with the tech, who was demonstrating the heat flowing successfully. I turned the car off, stepped out, turned it back on, and zero heat would come from the vents. Cold air at full blast with the dial set to 84° F. He was in shock.

Good going! I was never able to recreate this condition when mine did it. It would happen intermittently, I recall always on the same night of the week after work, wouldn't "cure" itself if I shut down and restarted, but the heat always worked as it should the following morning (I presume after the car had a chance to shut down completely).

But, as I mentioned in a previous post, the service tech was never able to recreate it, but wrote in their notes that they had updated the software, it recurred once under the new software but never again.

 

[AUTOMAN]

With regards to heater failure this I obviously a common fault mine was off and on for possibly months becoming very obvious when the cold weather started. I nailed the problem with a code fault reader. I would recommend you fit a new unit as second hand units are expensive and have unknown life expectancy. It appears a new unit could have a two year warranty?????