Hello all,
I'm new to Land Rovers and also to the forum.
I'm having some trouble with my drivers side o2 sensor and I'm looking for a wiring schematic/ pinout for the o2 sensors and the ECU.
Here's what's going on so far:
I was getting a 02 heater fault on the bank 1 sensor 1, so I replaced the sensor with no change.
I checked voltage at the connector and referenced the passenger side to compare and It appears that im not getting voltage on pin 1 as your looking at the connector (see pic) its the yellow wire on sensor or brown/ blue wire on harness.
I also tested behind the harness plug.
So im guessing its in the harness or the ECU?
If anyone can steer me in a direction it would be appreciated, I've spent some time searching the forums with no luck.


Thanks, Langley 1997 Disco 1 4.0

 

Hello Big! According to my work on my 96 Disco 4.0, Red (+)/White (-) are the heater wires and Black (-)/Yellow (+) are the signal wires. With an OBD scanner we can see real time O2 signals and fuel trims. Do you have a scanner?

I spent a lot of time tracking down problems with O2 sensors. Turns out we get really poor gas mileage (~9 mpg) with O2 sensor problems. I get 14 - 16 mpg now that the problems are solved. The OBD scanner was the key to solving the problems, (and changing the bad sensor). Now I can check my long term, short term fuel trims, and O2 sensor signals from time to time and see that everything is A OK.

Does this help? There are files available for the Electrical Test Manual (ETM) with wiring diagrams, component locations, and test procedures, just make sure you look at the correct year/model. I am not sure where to find the files to download, but I'm sure someone in the forum will know.

 

Hi John,
Thanks so much for the reply! so it looks like I have an open on the yellow wire (signal +) so I just nee to figure out where that pins out on the ECU.
I have a Carsoft scanner and my Torque app on my phone.
I REALLY need a wiring diagram.

So as I was troubleshooting the sensors today my starter went out, I love my British Ford hahaha!

 

Here, see if this lines up. U is blue, B is black.

O2 sensors from etlp97 manual

 

All the manuals you will probably ever need can be downloaded from the google drive linked in my signature. Help yourself.

 

Thanks so much! this will be very helpful and I will keep the post updated when I figure out the problem.