2015 Mustang Dash litup like a Christmas tree, car runs fine, signals stopped working, AdvanceTrac, ABS, and hill start assist turned off

[stephensatt]

This is a real good one. After all this rain, and I want to say it may be connected, wife's car dash lit up like a tree, but the car runs fine.

ABS light, restraint control light , Parking brake light, both traction control little car symbols both sides of the shift indicator comes on, then the messages start to flahs in the center console, "Hill Start Assist not available", "Advancetrac Service", "See Manual", come on, keeps flashing them. Oh, and I cannot activate my high beams or the turn signals, but get this. If I turn the car to just ON, and don't start it, the high beams work, so its like it turning them off, maybe to force you to take it in for service.

Troubleshooting I have done so far is check all the fuses, both boxes, tested all the relays with my relay tester. Interestingly enough, when I turn the car off, I heard relay #82, thats the "power control modules relay" making a buzzing sound and was hot feeling. Thats on the big fuse/relay box under the hood, so I replaced it with a new one, and the new one doesn't make any noise but I still get all the same codes. Also relay #69, the Auxiliary power point relay, and the only relay that is colored blue does not pass my tester, however, if I put in a 5 pin relay in its place, I get 2 codes specifically for that relay showing a open ground or short, so I put the blue on back in and the code goes away. Geeze, car only has 80k miles, so I know the electric steering is fine, and it works fine. If I remove the relay #82 altogether, then the power steering is turned off, and you can't turn the wheel, so thats my test of the power steering electric rack n pinion.

Forscan gives me codes:

Code: P062C - Internal Control Module Vehicle Speed Performance
Code: U0151 - Lost Communication with Restraint Control Module
Code: U0212 - Lost Communication with Steering Column Control Module
Code: U0121 - Lost Communication with Anti-Lock Brake System
Code: U0131 - Lost Communications with Power Steering Control Module

Its as if maybe something got loose or got water in it, but like I said, car runs fine, but the signals don't work. Brake lights work fine.
Its not driveable because of the obsessive dinging.

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[SHOdaddy68]

Looks like there is lot of ECM (computer) issues here. My guess would be same as yours: something got wet that should stay dry. You may need a deeper diagnostic into the CAN system which is how all the different ECM's communicate with each other.

 

[stephensatt]

Its driving me up the wall because nothing is obvious about this. There is nothing I can point to and say "oh there it is" because the car runs, but its certainly not going to pass an inspection with the blinkers shut off and ABS, traction control turned off and beeping all the time. At 80k miles, ya think the car would hold up better, and when I type in all these codes, I get a ton more F-150 websites and forums with this exact problem, and they all point to harnesses and drying stuff out. If it were my car, I wouldn't care as much as I can drive the truck until I can diagnose it, but this the is the Wife's only car and daily driver and she is having to use my car as a result so I gotta fix this soon.

So I am going back out there right now and start looking at harnesses and boxes. I had the wheels off yesterday and tested the ohms on all 4 ABS wheel sensors, all measure 450-452k ohms, so I think they are all fine and don't get any codes on the wheel sensors. Someone said to check the parking brake connector, apparently thats an issue also that causes similiar symptons, dunno how.

Its frustrating because I cannot find a single thing wrong anything I check. The 50 or so fuses the car has, all 4 kinds are fine. This is a far cry from all the Foxbody Mustangs I have owned, which were so easy easy to repair. Yeh I am missing that 1990's EEC-IV computer right now and actual mechanical relays to control the blinkers and lights. Thats why I bought the V-Linker cable and Forscan. I will have to see how to look at the CAN system now. Forscan wouldn't let me look at the ABS as if that section was missing from Forscan but I don't think you have to pay for that feature, dunno.

 

[MrMike]

Forscan wouldn't let me look at the ABS as if that section was missing from Forscan but I don't think you have to pay for that feature, dunno.

I'm certain you don't. I just had it plugged into my Bronco and Mustang in the past two weeks, and the ABS module showed up on both. Is it listed at all?

Edit: Added screenshot, this is from the Bronco but both cars have an ABS module.

 

[MAGS1]

Ok, let’s eliminate another easy one. Original battery? Does it labor to crank? If you’re able, check the battery voltage (car on in accessory mode but don’t turn it all the way on). The major auto parts stores can also do a battery health check (most do it for free).

 

[stephensatt]

Actually this is good advice. Let me check on that. Car cranks fine, everytime, but let me disconnect it from the battery, and while its sitting disconnected I will put my checker/charger on it and check the date and run a charge on it just to be sure. I have a couple of the high end fancy Schumacher digital chargers and a OEM Tools tester and I will let ya know. Trying this now. Thanks for the reply.

 

[stephensatt]

I'm certain you don't. I just had it plugged into my Bronco and Mustang in the past two weeks, and the ABS module showed up on both. Is it listed at all?

Edit: Added screenshot, this is from the Bronco but both cars have an ABS module.


Here is my screenshot. I cannot click on the blue ABS link on the right hand. Doesn't popup anything at all.

 

[stephensatt]

Battery shows 60% charge on charger but I have been starting and stopping the car many times in the garage. Its a Walmart Everstart MAXX battery, born on date 7/20, so its 4 years old, enough for me to go buy a new one right now even though car cranks right up. No corrosion on the connectors, everything looks new cuz thats how I roll with the dielectric grease. The OEM Tools digital tester, says its putting out 548 CCA, and its rated at 600 , says GOOD, and needs a RECHARGE, says on the screen. If only it were this simple. I am going to buy a new battery, its old enough so thats a no brainer as far as I am concerned. I will let yall know. Thanks for the advice. Eliminate all the obvious stuff first.

 

[MAGS1]

Battery shows 60% charge on charger but I have been starting and stopping the car many times in the garage. Its a Walmart Everstart MAXX battery, born on date 7/20, so its 4 years old, enough for me to go buy a new one right now even though car cranks right up. No corrosion on the connectors, everything looks new cuz thats how I roll with the dielectric grease. The OEM Tools digital tester, says its putting out 548 CCA, and its rated at 600 , says GOOD, and needs a RECHARGE, says on the screen. If only it were this simple. I am going to buy a new battery, its old enough so thats a no brainer as far as I am concerned. I will let yall know. Thanks for the advice. Eliminate all the obvious stuff first.

Figured it would be an easy check (and hopefully a resolution). These cars start acting goofy when the battery starts to go.

 

[stephensatt]

New battery did not fix it. I erased the DTC codes but they come back immediately within seconds of erasing them. Same exact codes as I posted at the top of the thread. What I find interesting is this steering wheel code and control module problem. I cannot hit the OK button on the steering wheel for the alerts on the dash which shows I can hit OK to stop the alert. It doesn't respond to that, neither the radio either or the turn signals respond to steering wheel inputs. The paddle shifter works fine but I can only activate bright lights if I turn off the car, not in RUN mode. Car runs great though. Drove it around the neighborhood with no other issues. Seems pretty odd seeing how the computer claims to lost communications with everything ABS , Steering, Restraint controls. Parking break test through Forscan works fine. You can set a filter and see the status of all the braking including the parking brake and they respond instantly on the scope.

ABS section and module seem to be completely missing from Forscan. Does't pick up any ABS codes other than U0121 which says "Lost communication with ABS", so I guess I cannot activate that part of Forscan unless it sees ABS on the car.

 

[ORRadtech]

This is why I prefer a scan tool over Forscan. A scan tool is going to show all the modules and whether they are Comunicating with each other. It will show in tree form what's online and what is not. You can then use that info and the car's wiring diagram to start eliminating problems.
I think you are looking at one of three things. Water/corrosion in a plug somewhere, a bad ground or possibly rodent/wire damage.
These cars are so interconnected a wiring issue on a completely unrelated system can bring down several systems.
As a side note, regardless of battery condition, you should always hook it to a charger when hunting for an electrical/electronic problem. Modern cars are very sensitive to voltage and low voltage can lead to unnecessary rabbit holes.

 

[stephensatt]

I went with Forscan simply because it seemed to do all the Ford stuff for just $35 for the cable and I have a laptop. Is there a scan tool you recommend?

If I am going to spend the money it would be great if it does Nissan and Ford if thats doable because thats what I have, Nissan and Ford. Its my understanding Nissan's "consult" is also a proprietary protocol.

Putting the Mustang up on my Ranger lift to pull the plastic undercarriage off and get access to the rack. Maybe it will be obvious. We had torrential storms and rain here in Houston this past month and thats when it started after driving through a bunch of rain. Humidity and heat has been something else with 90F days 80% humidity.

 

[MAGS1]

This is the one I picked up last year but Amazon has plenty to choose from

https://a.co/d/gJjP84z

 

[ORRadtech]

Forsca has its place and can absolutely do things most scan tools cannot. The thing about code readers and scan tools is they start inexpensive and go to several thousand dollars. The inexpensive ones do little more than read codes, the more expensive they get, the more they will do. Up to just short of manufacturers proprietary devices. I found mine on sale on Amazon for about $350 and it will do quite a bit on 90% of brands out there. If I were to buy another it would probably be in the $800-$1000 range. It seems like the more you can see and do the more you can see the usefulness of more abilities. You just have to decide what features you want and how much you want to spend.
Autell is a good brand as is XTool, Launch and TopDon.
Oh, and one other thing, some require updates every year or two. I try to avoid the ones that have a charge for those updates.

 

[jloshotz]

Just tossing it out there, since A LOT of this points to steering related controls…..it’s making my brain lead toward your clockspring. Just a guess.

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