[faz]

Hi everyone, I appreciate some help / any feedback on this.

My 2018 (B46 engine) with 52k miles on it, threw a check engine light code:

109001 coolant temperature sensor signal short circuit to B+

What started as a search on how to get to the sensor and replace it, turned into a wiring harness damage by rodent.


I started by doing a search and I came across this post [[ X3 B46 Coolant temp sensor ]] that has info kindly provided by mattsheng with PDF of the process involved to replace the sensor. As per that PDF file for X3, lots of items need to be removed and put aside just to get to the sensor.

(should be fine, does not look too complicated but just many many pieces to be removed and then put back in.)

I was trying to see where the part is and if there is an easier way of getting to it, I tried taking some pics and squeezed my iphone in the engine compartment and video'ed it... and to my absolute surprise, I see that the wiring harness for the connector cable is damaged as a typical rodent damage. See pics below.


Question: I am assuming the damaged wire is the one that is going to the sensor. Would I be able to cut the damaged part out and replace that portion with some wires?


Also, are there any tricks or easier way to get to this area without removing too many pieces? I am assuming since I have to work on the wire, I need to take the time and follow the X3 PDF instructions where applicable.

[fe7565]

I do not know an easy way to get to the wires, but someone will have to get to them. Either you, or you pay someone.

But wires are just wires so joining them back should not be an issue. Sensors wires do not carry big loads, just get about the same size diameter, or join the existing cut wires.

In some cases you can replace the entire harness with a DIY harness, if you know where the two ends connect (i.e. wring diagram), but since you only have a pin-point break and not general deterioration of the wire insulation, you can do a pin-point repair instead of an entire harness. Also, since this harness is in the engine compartment, getting to the two ends to replace the entire section may be more pain (wire connectors/pins, etc) than getting to the area that was chewed up.