Been working on the son's Rover, trying to eliminate a plethora of codes. While installing all new O2 sensors, I see this plug on the right side (above) the transfer case not connected to anything:



Can't find anything that it connects to? Looks like it's wires run to the rear of the vehicle, but can't tell where. Not an easy place to see or feel around either. Oh, and the prior owner had the trans rebuilt last year---most of the wires have been ripped from their mountings and are just hanging loose.

Second question: replaced ALL FOUR O2 sensors with new Bosch sensors. Previously had fault codes for both upstream sensors. Now the Bank 1 upstream sensor reads ZERO! I made sure the connector was very clean and also sprayed full of quality electronic cleaner. Here's what the Ultragauge shows:



Any ideas welcome. Thanks

 

Just last week, I replaced my son's upstream O2s and got the same reading(no reading).
I got under it and slightly pulled the wire and it unplugged. I put dielectric grease on the connector and this time made sure it clicked together. In my haste, I had not made sure the connector clicked shut. Immediately cured the no reading. Just a thought.

 

On the unidentified plug, From what I have found out. They are prewired for any and all options, whether they are installed or not. Although it looks pretty clean, like something was plugged into it, I will look under mine tomorrow and see If i can see that one.

 

I don't think that goes to anything. I have one of those in my truck too.

 

Just looked suspiciously clean to me. I'd expect it to be full of Montana desert dust after 2 minutes driving where I live.

 

That was my observation, also.

 

That connector looks like C0684, which is for the neutral transmission sensor -




Check the wiring colours, they should be - Black, and Black with a Pink trace.

.

 

Thanks for the info and the pic! However, tracking down the other plug (if it does exist on mine) is going to be extremely difficult without some tiny mirrors, or one of those flexible lighted scopes....or dropping the trans.