Compustar alarm removed, now problems

Crew - calling on your expertise here…I’m at a loss.

I bought a truck (2020 1794) that had a Compustar alarm/remote start installed. I don’t want it, so I took it to a local alarm shop to uninstall. They did the job and now the “VEHICLE CUSTOMIZATION” page in Settings is greyed out and inaccessible.

What could have possibly triggered this defect? Any thoughts?

 

Are you checking the vehicle customization page while driving? Some settings are only accessible/changeable when in park with the engine running.

 

No. I’m parked. Tried both engine running and not.

 

Damn. I'm not sure then.

I know @RainMan_PNW posted up wiring diagrams somewhere. That might be a good place to start hunting.

 

How that alarm was tied/hacked into the truck's wiring, and how they removed it, are subject to a lot of variables. I'm not familiar at all with aftermarket alarm systems or how they may be connected into things.

The wiring diagram thread is here:
Ultimate TUNDRA Wiring Diagrams Collection | Toyota Tundra Forum (tundras.com)

There's a chance that upon removal they've interrupted the actual park sensor signal going to the head unit...or any number of other wires.

I would work on getting my hands on the installation instructions for whatever alarm was removed so you can track down all the locations where it was hacked into the factory wiring, and then start chasing down those wires.

Or take it back to the shop you paid money to remove it. Seems to me that if they specialize in that sort of thing that they should also stand behind making sure when it's removed that everything functions as it should.

 

Wow! Incredible feedback...thanks for the link!

Follow-up question...if the park sensor was interrupted, we should surely see some other faults, right? I haven't done a full inspection of the head unit menu, but I didn't notice any other sections greyed out...ones which would normally be disallowed during driving.

 

Honestly, I don’t entirely recall what settings are and are not tied to that. I took the HU out last fall and replaced it with an Alpine

 

Probably not. If its just the parking sensor to the headunit, then the HU just thinks your in D. Have you tried other functions? Try to installed a new Phone. I know that for that, it can't be done unless you're in park.

 

This....

I would agree with the other posts that for some reason the truck's infotainment system doesn't think it's in park or something similar. Sometimes cars use a speed-sense input (can't change settings unless you're under a certain speed, usually 0). Most remote start/alarms interrupt a factory wire somewhere in the installation, and it's very possible wires were cut out for the alarm that they didn't trace all the way to the source. This might lead to a wire that is still interrupted. I know for my truck on the remote start, I had to interrupt a wire under the glove compartment to allow the keyless entry to work when the truck was running.

The only other one I can think of is a CAN data wire going to the head unit might be interrupted somewhere.

I wish you luck, wiring issues are such a pain to trace out sometimes.