W204 High/Low voltage problem
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C180 2013
W204 High/Low voltage problem
(W204 2014) So when I start the car and during my first gear shift from 1st to 2nd (automatic), the HU supply voltage goes to 15V and Supply voltage to 12V after both of them being constant at 14~. During these few seconds the screen and lights flicker with abs warning issue. This only happens once after the car is turned on and during first shift, if I drive for a while and go from 1st to 2nd again nothing happens.Any idea why?
Last edited by chahoud t; Aug 6, 2023 at 05:17 PM.
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From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
USE MB SCANNER
(W204 2014) So
when I start the car and during my first gear shift from 1st to 2nd (automatic), the HU supply voltage goes to 15V and Supply voltage to 12V after both of them being constant at 14~.
During these few seconds the screen and lights flicker with abs warning issue.
This only happens once after the car is turned on and during first shift, if I drive for a while and go from 1st to 2nd again nothing happens.
Any idea why?
when I start the car and during my first gear shift from 1st to 2nd (automatic), the HU supply voltage goes to 15V and Supply voltage to 12V after both of them being constant at 14~.
During these few seconds the screen and lights flicker with abs warning issue.
This only happens once after the car is turned on and during first shift, if I drive for a while and go from 1st to 2nd again nothing happens.
Any idea why?
Go ahead scan the car to retrieve faults
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The same Problem
(W204 2014) So when I start the car and during my first gear shift from 1st to 2nd (automatic), the HU supply voltage goes to 15V and Supply voltage to 12V after both of them being constant at 14~. During these few seconds the screen and lights flicker with abs warning issue. This only happens once after the car is turned on and during first shift, if I drive for a while and go from 1st to 2nd again nothing happens.Any idea why?
Thread Starter
Newbie
Joined: Jan 2021
Posts: 12
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C180 2013
First replace both front and rear batteries, the main culprit could be the rear battery. I did so about a year ago no problems anymore except for a split second of flickering lights when i first drive , no resolution for this yet.
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They say to me and is logic to change alternator regulator because battery can not increase voltage more than 12v and in my case the voltage is increasing more than 12v
Thread Starter
Newbie
Joined: Jan 2021
Posts: 12
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C180 2013
i believe the problem was the rear battery was dead and the alternator was working higher voltage to compensate it at start. You can know its the rear battery because eco mode will remain yellow on screen. It should be green when you drive and do full brake the car will shutdown as it is supposed to in eco mode.
Last edited by chahoud t; Dec 21, 2024 at 03:34 AM.
Out Of Control!!
Joined: Apr 2019
Posts: 12,002
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Voltages from 12.6V to 14.9V are 100% normal!
This does not cause brake faults... it's a separate issue with faulty module.
Use a scanner to retrieve faults.
> Don't believe me... :
Replace batteries + alternator then you'll get no difference: 12.6 to 14.9v.
✌️
This does not cause brake faults... it's a separate issue with faulty module.
Use a scanner to retrieve faults.
> Don't believe me... :
Replace batteries + alternator then you'll get no difference: 12.6 to 14.9v.
✌️
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2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
And avoid using the ECO Start/Stop. Does very little for gas mileage and lots of harm to the rest of the car.
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2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
