When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I ve had almost same issue. But while turning car off. As soon as i pushed engine off, all dashboard lights came on. I could not lock the car and did not test anything else but turned on the car again. Then everything got back to normal. I did not drive it yet, tomorrow i will check again. I have lately replaced auxiliary battery, main battery is 3 years old.
IS main battery feeding all except gearbox which is fed from auxiliary battery?
The issue for mine ended up being the CAN Bus Terminal, these are located under the kick plate next to each seat, right under where the door closes. What happens is the drainage system in the car gets clogged with debris causing rain to drain in the car instead of draining out of the car. It pools up under the carpet where these terminals are causing short circuits between the SAMs. I dealt with this issue for years, with a lot of help from good people here, it was self diagnosed and fixed that's why I'm replying to pay it forward. Hope this helps.
I ve had almost same issue. But while turning car off. As soon as i pushed engine off, all dashboard lights came on. I could not lock the car and did not test anything else but turned on the car again. Then everything got back to normal.
I did not drive it yet, tomorrow i will check again. I have lately replaced auxiliary battery, main battery is 3 years old.
IS main battery feeding all except gearbox which is fed from auxiliary battery?
What AUX batt can power depends on what size it is. They went from Small to Medium then to Extra small.
Normally the whole car exclusively feeds from the alternator including the transmission controller.
-- The small in dash AUX is said to help shift gear selector under extreme conditions.
-- The medium in trunk AUX is used during ECO restart to power the car reduced load while Main cranks the 600A engine starter.
-- The tinny AUX in footwell is a 4. Farad set of capacitors instead of prior lead-acid batteries.
The eye opening Christmas tree sounds like a perfect example of a glitched car network.
You should scan your car in hope to see what module got soft-crashed.
As soon as the VIP's get a chance to sleep (power cycle ie. Reboot!) the car is ready like nothing happened.
The remaining upset modules are SAM for which you'll want to disconnect MAIN + AUX Batts before Main gets drained down.
Last edited by CaliBenzDriver; 10-05-2022 at 08:34 PM.
The issue for mine ended up being the CAN Bus Terminal, these are located under the kick plate next to each seat, right under where the door closes. What happens is the drainage system in the car gets clogged with debris causing rain to drain in the car instead of draining out of the car. It pools up under the carpet where these terminals are causing short circuits between the SAMs. I dealt with this issue for years, with a lot of help from good people here, it was self diagnosed and fixed that's why I'm replying to pay it forward. Hope this helps.
Yes! This is what I've been looking for. I've had the same issue with water. Is this why the mechanics are telling me they are getting all these electrical codes? Please tell me how to fix?
I am not a DIYer, unfortunately. I'm a retired social worker trying to keep my car going.
Thank you for all this information, yes I bought a used prefuse box and still have the same issue. I have a picture of the old one below to show the difference in mine and the one you are showing. Notice the relay plugs come out the side and the four single wires at bottom go straight in (not horizontally). I tried to removed the relay (A0035420019) with no success, you can see it has a similar diagram on it like the one you just showed me. Is this the same relay you are referencing? You can see I completely destroyed the prefuse box in this picture trying to take out the relay so this cannot be re-used. I still have the one in the car and can work on that one, do I have to remove prefuse box from car to test voltage? I really appreciate your assistance here, I have a friend coming over tomorrow with a voltage tester to follow your instruction.
How did you actually remove the yellow plug on the side? I cannot get it unplugged to save my life and no idea what kinda plug it is
10-05-2022, 08:05 PM
