I'm not sure about Rovers but usually vehicles will have a couple CAN lines to send information. For instance, from engine sensors to the ECU, or from the ECU to the data link connector. It kind of sounds like you may be missing connection to one of those wires. The biggest problem with those wires is, you really need an oscilloscope to see the signal on them. They often have patterns of low voltage on/off square waves that are impossible to see with a multi-meter.

 

Finally got home from work and checked the wiring diagram. I am betting the problem lies in connector C0286, located in the harness inside the plastic wrap tube, just ahead of the blower motor on the right side. Some fairly delicate surgery is in my near future. Let me have breakfast and another cup of coffee and I'll keep you posted.

 

That is such an awkward spot to work in. It will bring out your inner gymnast. Or, if you have no inner gymnast and can't stand tight spaces (me) it will bring out the inner beast! Good luck!

 

Despite finding and repairing this, I still have limited communication with ScanGauge.

 

Geez. Is that the cable from the ECU? If so I can only imagine the pain. I seriously hate messing with the dash wiring. Well, you either have a grounded wire or an ECU issue, neither of which I'm much help with. But if you're on a mission, you'll find it. Sorry I can't be more help. So far, shoving the wires into the back of the connector has worked for me. I'm sure I'm well along to path to your situation so please post the fix if you find one.

 

hmph. had the exact same trouble with my UG for 2 days last week (2 rainy days btw). had tried unplug / re-plug to no avail. then on day 3 the unplug / re-plug worked and have had no problems since (nor any in the almost 2 years I've had the UG prior to last week). weird.

 

At this point, I am trying to think of anything it could be other than the ECU. The OBD II port has 4 wires: 2 grounds (both test good) a purple power wire, and a pink wire to the ECU. All connections from OBD to ECU cleaned on pink wire, which transmits some data, just not all of it.

A new ECU, for me, means a used one, a quote from the dealer (150 miles away) to "flash" it after I install it in the parking lot, and approval from the Minister of Finance for the whole deal.

It may be some time before I have this resolved.

 

Further contemplation leads me to believe my troubles lay in header C0286.
https://landroverforums.com/forum/di...-repair-57435/
I had similar corrosion in the cap, which functions as the bus-bar of the header. Even though I cleaned it, I'm guessing the bridge is broken some place.
Now the question is: do I contact some supplier, or tie the 8 pink wires together with a big honking wire nut or solder? (The latter is fast and free, the former would require more patience than I have ever been able to muster.)

 

Always try fast and free! The minister of finance doesn't care about work hours, as long as they are not compensated.

 

If it were me, I'd opt for the quick-fix to see if it solves your issue. Meanwhile, I'd be ordering a generic busbar/terminal block as a permanent solution. Either way, you're going to need to re-connect the wires you're cutting.