Need help figuring out a problem

[RJameson]

I have a 2014 King Ranch Expedition. I bought it used with 65000 miles in 2017. A few months after buying it, I began to experience the following randomly, lasting anywhere from a few seconds to almost an hour. So far the dealerships can't identify the problem.

The alarm will sound and I will get error messages alternately displayed: "Tire pressure monitor fault; Trailer brake module fault; Door ajar"; Brake light stays on; Tire pressure light blinks and then stays on; When these errors occur, my runners will not deploy, the air will blow but will stop blowing cold, and my backup camera will not work, or once my backup camera was displaying while I was driving forward.

Does anyone have any ideas? This is very frustrating.

 

[TXFRDOwner]

Sounds like your canbus network has gone haywire.

Could it have been in a flood and they didn’t disclose that to you !!!


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[jeff kushner]

Since electrical bugs are generally difficult to isolate, I would suggest beginning with the easy stuff. I would disconnect the battery and remove all the fuse and relay covers, remove, check, clean and reset each fuse & relay thereby eliminating a bad fuse/relay or bad contacts.

At least it would be a start but smarter folks here might have better suggestions?

jeff

 

[richie]

You would be surprised at some of the problems a cheap cell phone charging adapter can cause and it is a simple thing to check out.

 

[Motorcity muscle]

You would be surprised at some of the problems a cheap cell phone charging adapter can cause and it is a simple thing to check out.

My charger messed with tire monitor system, replaced lighter with USB port, problem solved. Sounds like bigger issue with your truck, water being a possible cause, are seat frames rusted?

 

[stamp11127]

All the electronic razzle dazzle of today is sensitive to voltage fluctuations or lack thereof. First things to eliminate would be battery condition & state of charge then the charging system. Battery voltage needs to be above 12.4 volts to be safe with engine off. With engine running you should see a charging voltage between 13.5-14.5 volts dc.

 

[Trainmaster]

You may also try rebooting the thing. Disconnect the battery for a few minutes, short out the cables for a few seconds to discharge any capacitors that hold memory and hook it all back up.

 

[MuddySpokes]

If the charging system and battery are good, consider getting some software that will see what the computer sees in real-time. Chances are good that the vehicle is complaining about something and it is just a matter of looking at the symptoms to start focusing on the likely culprit(s).

As mentioned, flooding is withing the world of possibilities. Might consider running the VIN to see where the vehicle was previously registered and if there were any significant weather events in that area.

 

[1955moose]

By law in all 48 lower states, and probably Alaska and Hawaii too. A seller has to report flood damage. That's not to say an unsavory individual won't try to yank up the carpets and every large area, and try to dry it out. You or a shop may have to do a little carpet yanking of your own. If you do find wetness, take plenty of pictures. Hopefully this is not your issue.

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[bobmbx]

By law in all 48 lower states, and probably Alaska and Hawaii too. A seller has to report flood damage. That's not to say an unsavory individual won't try to yank up the carpets and every large area, and try to dry it out. You or a shop may have to do a little carpet yanking of your own. If you do find wetness, take plenty of pictures. Hopefully this is not your issue.

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Carfax works pretty good in determining where the vehicle has been, and when it was there.

 

[1955moose]

Not from what you guys have said here. A lot of vehicles that should have, didn't get reported. With all this computer tech that can find out your fibbing on your resume a little to get back to work, a company that's supposed to be a straight shooter, isn't always.

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[G213]

All good thoughts and I agree, start with the basics.

- Disconnecting the battery. Disconnect both terminals and connect the two leads from the car with a jumper cable. Let sit for 15 minutes. This will drain all capacitors and basically be a hard reboot for the electronics.

(DO NOT do this until the battery is completely disconnected. To be super safe, put something between the cables and the battery so they won't accidentally touch the battery posts...or just remove the battery from truck and set aside)

- Reseating all fuses. As you pull fuses, get your flashlight out and inspect the contacts inside the fuse box. You can replace a fuse, but rusty or damaged contacts are easier to miss.

Another thing you can do as a part of your detective work, grab a flashlight and start looking behind panels, under seats etc. for grime or water spots where it shouldn't be. Also check interior metals (such as seat frames) for rust. These would all be signs of flooding.

You mentioned that you bought used. Are there any aftermarket accessories? (alarm, headunit, remote start, backup camera etc.) Improperly installed accessories are notorious for causing weird electrical issues.

Any evidence of previous modification to the truck? (things like spliced wires, unused T-taps, leftover velcro or double sided tape, broken panel tabs, wires to nowhere, holes in headlight covers) Someone may have cobbjobbed an install or shorted something when pulling it out.

Some other thoughts....

- Does this all happen at one time or does something start first which then causes the rest to occur? For example, you listed the alarm first; does the alarm start to go off and then a second later everything goes nuts? If that's the case, I'd be focusing around the first system that fails.

- Are there any similarities to the instances when this has happened? For example, does it only happen when idling....or does it only happen in the rain....or only when you're accelerating....or only when the radio is on? Take a note of the current status of systems next time it happens and see if you can find any associations to future incidents.

- You mention that it started a few months after you purchased...have you installed or changed anything which may have caused it?

- Also, you mentioned it can last for a few seconds to up to over an hour. What causes it to stop?