My first step would be to hook up IDS/SDD. With that you can very quickly(relative term, this system is not fast) ensure that you have communications. Once in a session with IDS/SDD I would go straight to the diagnostic interface, it is in the service functions menu in SDD under a EAS based diagnostic session, and in the Special Applications menu of IDS.

This tool will give you all of the information you need right in one place. It is sometimes necessary to clear fault codes before the tool will work.

Based on what that tool says, I would move forward, most likely back to the wiring that was repaired.

 

Thanks Dave! Is there a way to properly clear faults in SDD or are we just talking about the "touching terminals" method using the battery cables?

 

Just to add to the conversation guys; another theory is the fact that they only replaced one height sensor could be causing some issues. LR came out with a bulletin a few years back stating if one sensor fails on the same axle (front, rear) both sensors are to be replaced as a pair. Just some insight...

 

So...what if we threw the old Psx-side sensor back on? I don't think it ever needed to be replaced; we did that before discovering the broken wires.

 

There was a bulletin to replace both at the same time, however it was not really to do it for any reason aside from preventing repeat repairs. The reasoning for it was this...

Say you're driving on a nice smooth road, the signals should be nice and smooth, but if the RF sensor is reading erratically, it can throw a fault for that sensor.
Now if you're driving on a somewhat bumpy road, and the LF signal is nice and smooth, as in it is not responding to minor changes in height, it will then throw a fault for the RF sensor, as it see one smooth signal, and one rough signal.

Any fault for a height sensor signal can be triggered by either of its adjacent sensors, ie RF fault could actually be a fault of the RR or the LF sensors.

AS to clearing the faults, it should be done with SDD, a few clicks and it'll be done, there should not be any stored faults in it, aside from a lack of calibration data fault. But like I said before, I expect to see an issue with the signal coming back due to an installation problem.

 

Dave, can you please tell me the menu path to clear faults? This may sound silly but I don't think my LR Techs know how to do it. If there is a hardware issue it's the wiring. I looked at each sensor exhaustively yesterday and they look fine in terms of their housings and how they are mounted.

Is the connector "oriented" or is it possible for it to have been plugged in backwards? Just brainstorming here...

 

If the tech doesn't know how to clear fault codes, you need to find a new tech.

Depending on software version they're using, the path is different. But in SDD you go under a diagnostic session, based on both "Electrical -> Instruments -> Warning Lights" and "Chassis -> Suspension -> Vehicle Dynamic Suspension"

Then into the Events tab, which will show you any and all faults, two different locations for related and unrelated, however that only applies to what was entered as the symptoms. To clear faults, you would go to the Service Functions tab and select Clear all fault codes.

The connector can not be plugged in backwards, unless really forced, there is a tab, but it is plastic, and it would be possible to deform. I would be looking more so at the wires being connected to the harness properly.

 

Thanks. Lot, Dave. They used a pre-wired wiring overlay... So my suspect area is where the wire ends on the overlay were spliced into the existing wires. Maybe the shielding between the wires is not sufficient and there is some electrical interference mucking up the signals. Anyway...some good info here to attack with tomorrow.

 

I doubt it's interference, as this type of signal is not heavily influenced by either RF or inductive interference. However, the overlay that was installed is a somewhat generic overlay. It is the same part for each sensor, all of which have different wiring colors, so it is not terribly difficult to install it incorrectly.

In the diagnostic interface, a mis-wired sensor would show up as either a full 5v or 0v as the sensor reading, depending on what was done.

 

What voltage should the sensor normally read? Good info on the generic nature of the overlay; thanks.