jsum434

I have had no problems besides normal wear items like brakes, tires, etc with this car. I've long considered it to be the greatest highway car ever made considering I often take same-day trips of 400-700 miles carrying up to 1500lbs of equipment and it rides nice and has been reliable. Yesterday, I was on my way back to Pittsburgh from Columbus and over the course of about 10 minutes, all of these things happened: "blind spot inoperable", "cruise control deactivated", "pre-safe inoperative", then I got all lights on instrument cluster and speedometer and tach at 0 even though the car was still driving, followed by red-lettered warnings about not shifting gears and the parking brake. Finally, I lost all power and pulled onto the shoulder. The car would not restart and the DNRP was greyed with no white square around any of the gears while the red warnings about parking brake and "transmission not in P" continued. I tried removing the keys, opening and closing door, locking and unlocking, anything that may reset whatever went wrong, but nothing worked. I gave up and called AAA for a tow. After waiting 45 minutes for a call-back and getting tired of waiting, I started checking fuses. Everything under the hood was fine, 116 under the rear seat was blown. This fuse is described as being part of the lane assist function or something. I swapped it out with the passenger airbag fuse, but the car still didn't start. I then repeated the whole door open close, lock unlock and start and it started. I drove it all the way home, about two hours drive, with no issues except a persistent "blind spot inoperable" message and the orange lights in the mirrors constantly on and the passenger SRS, which I obviously knew the reason for that. When I got home, I turned it off and it started right back up.

This morning, I got in the car and it would not start, same warnings about transmission not in P and parking brake. Checked all fuses again, nothing blown, replaced passenger airbag fuse. 15 minutes later, the car started up without error. Another strange thing is that while the car is unable to start, I am also unable to use the buttons for the 2nd or 3rd row seats. Normally, I can use these buttons any time without even turning the car on.

I've read all of the threads here related to these things, but has anyone ever had all of these things happen at once and figured out what it was? The batteries were replaced in 2019 and test good. I checked the battery compartment and spare tire area for water, everything is dry. I'd much rather solve this problem without taking it to a dealer and I'd like to keep this car until the wheels fall off, but I need it to be reliable.

chassis

Scan for codes, preferably with XENTRY. An Indy shop or dealer can do this for a diagnostic fee. You can scan for codes with a basic scanner and may or may not get the full story.

Weird and unexplained electrical problems are commonly related to weak or failed batteries or water intrusion. Check under the front and rear footwell carpets for water intrusion, possibly because of sunroof or door/window leakage. How are your perimeter seals and liftgate glass/wiper shaft seals?

Did you replace both main and aux batteries in 2019? Who replaced them?

jsum434

April, 2019. Both batteries. They test at 12.4 and 12.25V with the engine off. I wouldn't expect a battery to cause problems like this 60 miles into a 200 mile trip, but I tested them anyway and assume they are fine.

chassis

What does your gut tell you this is? Who replaced the batteries?

jsum434

They were replaced by an independent shop I have been using for 20 years. I have a cheap scanner that shows no codes at all, but I think it is only useful for generic OBD2 codes for engine and emissions issues. Water was one of things I searched for because I found that to be a problem in similar threads, but everything seems to be totally dry. I checked the spare tire area, behind both panels in the rear corners and the underseat fuse and battery locations. The only other thing I haven't done yet is jack it up and visually inspect wiring under the car.

jsum434

Finding no water and assuming the batteries are good leads me to think a wiring problem or some defective part is able to wreak havoc on the entire car. These things are so complicated, I think I'd be better off with a 1960s van with points ignition and a manual transmission.

chassis

What is the history of this vehicle? How long have you owned it and who did you buy it from?

Ricardoa1

Possibly a bad alternator? After the battery drains you will get a no power condition.

acetaylor

Check your grounds from the battery(s) real close. Cable ends, body attachment points, etc. I don't know if fuse/relay blocks are grounded in any way but probably are as relays will need a ground to operate. So check them too. A good ground is required for proper electrical performance. Without it, all sorts of things will go cataywampus.

arsupisemnet

You need to do Xentry scan. Faulty module can put down CAN network.

jsum434

So, I got a little more info thanks to my neighbor having a much newer scanner than mine - he's one of those Dodge truck gearhead kind of dudes. I'll be checking every accessible portion of wiring harness and ground connections today. Seems like something is causing communication failures. I don't have a check engine light or any current errors besides the blindspot inoperative thing, but the car had the following stored codes: U0146, U0155, U0037, U1110, U0122. Along with the previously blown fuse 116, I'm hoping it is something as simple as a wiring issue on whatever systems that fuse leads to.

chassis

Glad you got some more information.

What modifications are on this vehicle?

arsupisemnet

Your machine is full of digital communication networks called CAN. One faulty module can bring network down. Unless you have original MB Xentry or similar test system you won't be able to chase it down. Simple as is.

mcoady1

Xentry definitely needed to pinpoint as certain modules may be drawing excessively, but my suspicion is a grounding issue or alternator. If the car goes haywire after hitting a bump I’d think a ground.

glad it’s not water, went through that sob story in a x164.

jsum434

I got under the car on Monday and started at the rear bumper checking every connection I could get to. Everything looked great underneath, surprisingly clean considering Pennsylvania winters are full of salt and grime. The right blind spot radar was difficult to disconnect, otherwise, things were easy to unplug and plug back in. I finally replaced the left control arm height sensor while I was under the car. The lower link cracked and separated several months ago and I drilled a small hole through both sides and put it back together with a zip tie while the replacement part was ordered. Needless to say, the zip tie worked so well, I never got under the car to put the new sensor on until now.

I found nothing suspicious under the car or in it, so I moved to the underhood area. On the passenger side wall, I did find two ground points that were very corroded, one of them has three wires and had a green powdery build-up on it. I removed both ground nuts, separated the one with three wires and wire brush cleaned the terminals, reassembled and put some grease on for good measure.

I drove it locally monday and tuesday with no problems and took it to Charleston WV and back today, which was like 450 miles round trip. Keeping my fingers crossed it is fixed.

Tiffany's GL450

Did you get a Photo of that ground point location? Might be a good idea to check mine as well. Is it where the Battery terminals are located?

Chad

jsum434

I did not take a photo, but if you look on the inside of the front right fender area forward of the underhood fuse box, you will find three ground locations with a rubber cap over the nut. On my car, the worst one was the point that has three wires, then the single wire that is down a bit lower, heavier gauge wire. The third one looked clean. The one with three wires has three round hole terminal ends that are sandwiched together and kind of joined with small metal tabs. They are easily separated and put back together and the corrosion was all over, between each terminal. The nut has four tabs almost like the setting of a ring, slightly bending one of them back is enough to sneak it out of the terminal.

drsanket2000

did you ever resolve this? I feel like I have same issue and can't confirm. can you please advise? thank you

jsum434

I have had no problems since cleaning the corroded ground points under the hood. It's been business as usual with trips to Tennessee, Indianapolis, Cleveland and multiple trips to Baltimore and DC area. I have to assume the problem is solved.

Jason Stewart

@jsum434 wondering, when your electrical problem presented it self, did it look at all like this?
Trying to figure out where to start with the problem I'm having that sounds similar to yours...

jsum434

Very similar. The tach going to zero and warning lights flashing were just before I lost power. I'm at 223,000 miles now and have not had any electrical problems since repairing those ground wires. I'm looking to replace this car soon, but still trust it. Just put over 1000 miles on it round trip to Knoxville this past Wednesday.