bjwhite wrote:

Success! I located the bad splice and while I haven't fully repaired it, I did jump it with some leads and did some testing and everything works as it should.

Thank you Martin for setting me upon the correct course--realizing that the 12v at the red wire in the brake light switch harness was key--along with the "half-operation" of things on that circuit.

The splice in question was in fact SJ1667, which is located on the right side front door (NAS LR3)....in the sill where the mass of wires is located, just before the turn upwards going to the grounds and higher up, the fuse box.

One red wire coming from the back of the vehicle, going into two red wires from the front in that sill area. They were taped with light blue electrical tape and the connection was completely severed--lots of green corrosion in what was left of that connection.

I am going to repair this with crimped butt connectors and waterproof heat shrink. All in all a completely easy fix that was a pain to track down. Thank you again Martin.
Brian

Greg9504 wrote:

Did you remove the hard plastic sill cover and expose the bundle of wires?

bjwhite wrote:

I know, I know. Brake light switch right? Not in this case.
I've been through many things to try and track this down, but now that winter is among us, I really need to fix it as the traction control is inoperable with this fault.

The symptom is this.... If I put my foot on the brake and start the car everything seems fine. However, if I remove my foot from the brake I immediately get a transmission fault along with Traction Control light on and amber BRAKE light (North American LR3). Using my IIDtool that code is U0416-86 (2F) Invalid Data from Vehicle Dynamics control module.

Upon further inspection I also get "P0504-64 (2A) Brake Switch A/B correlation" and "P0504-29 (2A) Brake Switch A/B correlation" which also makes it seem brake switch related.

I have two brake switches as I had replaced the original one due to normal maintenance and keep the original one in the vehicle just incase. Both switches behave the exact same way.

BUT HERE IS THE KICKER--which I think is the root of the problem. If I use the IIDtool to go to Live Values, I can go to the brake light switch operation under the Transmission menu. If I leave my foot on the pedal, the brake LIGHT switch function says ON and the brake switch function says ON. If I remove my foot the brake LIGHT switch function goes OFF and the brake switch function stays ON and this is when I get the transmission fault with no HDC, TC light, etc.

What boggles my mind is where to go next.

One little issue I noticed was during last winter, I was driving on a mountain pass on some rainy roads. Taking a high speed left hand turn, the TC kicked on just for a little bit. I thought to myself, "Wow, must be slippery out here." But later on, even as spring arrived and it was not as wet outside, on certain left hand turns, the TC would kick on--even when it was dry. Soon thereafter, this fault started and has remained throughout the summer.

I find that an odd occurrence...given the symptoms that happened just after this.

So...I've come to...bad or damaged wiring somewhere? Or...is this a symptom of the "Bosch Transfer Case ECU" behind the battery? I did check that and while I saw a tiny bit of evidence of wetness or water at the connector, the inside of the ECU box was as pristine as new and dry as a bone.

Anyway....have any additional thoughts? I'm going out to check 12v at the red wire at the brake switch....and is there anything else I can glean from my IIDtool?