[unvme]

First post here in a long time.
I was getting intermittent abs light on and code U0120, lost communication with ABS module. And of course lost wheel distance and speed codes. All were in ECU and TCU. Then it became a more permanent problem and the TIPM was getting the U0120 code also.
So... I've checked bat+ and grounds and ignition switch 12+ at the ABS connector, all good. Also ohmed out the can bus c wires from ABS to TIPM both read 0.4. So I was ready to order me up a used abs module and replace the electronic side of it. Until I noticed my reverse lights not working. Not sure when that started...
With a scanner I can see the ecu knows when I shift into reverse but does not command the reverse lights. I can turn on the reverse lights with the scanner so I know the lights work and wiring should be ok. Now I'm thinking TIPM might be at fault, or can the abs be causing this also.

Let me add in all other issues the car has right now, incase they may need related.
Dash lights dimmer was intermittent for months, would only work If I held left turn signal down, now they won't dim at all.
Navigation is stuck on a road I haven't been on since last weekend (probably caused of no distance or speed readings I hope)
Blend door and recirc actuators clicking (started 2 months ago)

Other then the last 2 months I have not had in issue with thre car at all.

It's a 2013 with 3.6 and has 142828 miles (mileage hasn't changed in 2 weeks lol)


Anyone with any ideas??

 

[Intrepid]

I'm guessing that all of the electronic issues may be caused by a bad TIPM or connections to it. Check all the connectors on the bottom of the TIPM for loose or corroded connections first. The age of the battery could be an issue also.

 

[unvme]

Thanks for the reply. I have completely removed TIPM and all connections. Opened the tipm up and looked around. All solder joints look ok, no corrosion and nothing looks burnt. The battery is less than a year old. When I still had access to abs module with scanner I noticed it's voltage was about half a volt lower then other modules but found no reason why.

I am currently doing a tipm "hard reset" hoping that may do something...

 

[unvme]

Well the "hard reset" on tipm did nothing.
I think I'll start by replacing abs module abs see what changes. Used from LKQ about $70 so it ain't that bad

 

[unvme]

Anyone have ANY idea why my reverse lights don't come on when in reverse??

I haven't replaced abs module yet(to lazy). But I don't think they are related.
Again no lights when in reverse, but scanner shows everything to be reading the trans is in reverse. Can also turn on reverse lights with scanner though tipm and they come on.

So so strange

 

[5rebel9]

Broken wire or bad circuit between the trans. range sensor to the TIPM or bad GROUND circuit in the TIPM printed circuit board for the reverse lights???
Just a guess, But as you asked for "any idea".And also printed circuit board pathway failure in the TIPM for the ABS problem is also my guess.
Time for serious wiring diagram needs to track out to fix before throwing some expensive parts at the problem.

 

[unvme]

I've ohmed out the can bus c wires from abs to tipm also checked all power and grounds, all ok.

The funny thing is. With a scanner the tipm will read when the car is in reverse, and with scanner I can turn the lights on. They just don't come on on there own. I'm going to get a used ABS module and change out the module only, not the valve body and pump side.
With all my research with Alldata and testing everything I'm pretty sure that will fix my abs, speed, and non moving gps on radio. Kinda hoping it will fix the reverse, but still stumped on that lol

 

[unvme]

Update.:
Just bought a used ABS module. I plugged it in only to the harness (did not connect brake lines, only for testing) and everything came back to life as normal. Speedo and odometer working again. GPS now moving again. And very strange, I still don't get why, the reverses lights work as they are supposed to.

I did reset the module with scanner and attempt a drive cycle, but the drive cycle would not complete due to lack of brake fluid pressure reading, again I did not disconnect brake lines from the bad unit.

So this Saturday, weather permitting, I'll swap the units and all should be good to go.