Voltage drops when accelerator pressed
Thread Starter
Newbie
Joined: Jul 2021
Posts: 2
Likes: 0
W204 C63AMG
Voltage drops when accelerator pressed
Hello.
I have a strange problem with my c63. With the car running, when I press the gas pedal, the voltage drops sharply. You can even see the lights dim.
When the car is turned off, the ignition is in position 2, when I press the gas pedal everything is ok, you can hear the throttles, the voltage does not drop.
link to the video below:
Someone had a similar problem?
Some suggestions what may cause the voltage drops?
I have a strange problem with my c63. With the car running, when I press the gas pedal, the voltage drops sharply. You can even see the lights dim.
When the car is turned off, the ignition is in position 2, when I press the gas pedal everything is ok, you can hear the throttles, the voltage does not drop.
link to the video below:
Someone had a similar problem?
Some suggestions what may cause the voltage drops?
Super Member
Joined: Dec 2009
Posts: 748
Likes: 93
From: Dhahran, KSA
2020 E 300 Coupe and 2019 GLS 400
Hello.
I have a strange problem with my c63. With the car running, when I press the gas pedal, the voltage drops sharply. You can even see the lights dim.
When the car is turned off, the ignition is in position 2, when I press the gas pedal everything is ok, you can hear the throttles, the voltage does not drop.
link to the video below:
https://youtu.be/wY2UCE7s9Sc
Someone had a similar problem?
Some suggestions what may cause the voltage drops?
I have a strange problem with my c63. With the car running, when I press the gas pedal, the voltage drops sharply. You can even see the lights dim.
When the car is turned off, the ignition is in position 2, when I press the gas pedal everything is ok, you can hear the throttles, the voltage does not drop.
link to the video below:
https://youtu.be/wY2UCE7s9Sc
Someone had a similar problem?
Some suggestions what may cause the voltage drops?
MBWorld Fanatic!
Joined: May 2015
Posts: 4,037
Likes: 1,012
From: Miami, FL
2003 CL 600
It only drops to 13v? That's not a problem.
Try it with the hood open. That locks out the alternator control, makes it charge full time all the time. See if it's the same. If so, probably normal. I've never bothered to troubleshoot any car that has voltage over 12.5ish when running, as that's normal.
Try it with the hood open. That locks out the alternator control, makes it charge full time all the time. See if it's the same. If so, probably normal. I've never bothered to troubleshoot any car that has voltage over 12.5ish when running, as that's normal.
Thread Starter
Newbie
Joined: Jul 2021
Posts: 2
Likes: 0
W204 C63AMG
I tried with the hood open, it's the same, I've also noticed that the voltage drops when I come off the gas pedal. You can see this in the video below. (I thought before that this was caused by pressing the gas pedal).
I also found that revs fluctuates when driving at the constant speed ie here at 110 km/h
Here you can see interior light dimming when car is idling.
I've started investigating this issue after last, more spirited drive when the ABS/ESP inoperative came on. It all went back to normal after switching the car off and back on, only CEL remained on.
Afte conecting car to xentry found 2 errors related with esp:
- C219700 one or more signals sent from control unit "Combustion engine" via the CAN bus is implausible
- C326600 Consequential fault
and two errors related with ME97 engine:
-0736 The position of the exhaust camshaft (cylinder bank 2) deviates from the specified value
-0073 Position sensor 1 for the accelerator pedal has a short circuit to positive
Thank you for your help
I also found that revs fluctuates when driving at the constant speed ie here at 110 km/h
Here you can see interior light dimming when car is idling.
I've started investigating this issue after last, more spirited drive when the ABS/ESP inoperative came on. It all went back to normal after switching the car off and back on, only CEL remained on.
Afte conecting car to xentry found 2 errors related with esp:
- C219700 one or more signals sent from control unit "Combustion engine" via the CAN bus is implausible
- C326600 Consequential fault
and two errors related with ME97 engine:
-0736 The position of the exhaust camshaft (cylinder bank 2) deviates from the specified value
-0073 Position sensor 1 for the accelerator pedal has a short circuit to positive
Thank you for your help
SPONSOR
Joined: Sep 2014
Posts: 3,647
Likes: 818
From: Worldwide
2007 Mercedes E63 AMG
sadly, many issues can cause this. if you've confirmed your battery is in good health and holding a 100% charge, and validated your alternator is correctly returning 13-14 volts from here on its a wild goose chase. one of my customers had an issue with a connector's pin arcing with a relay which was causing voltage to drop at random situations. it took him 6 months to figure out what the case was.
MBWorld Fanatic!
Joined: Oct 2007
Posts: 2,300
Likes: 381
From: Texas
10 C six trizzle
I swear some people just hunt and want to find problems with their cars. This is normal operation. This isn't a crappy 70s car that full fields the alternator all the time. It use algorithms to run the charging management system. Shuts the alternator off temporarily during acceleration. Helps with emissions and more power output. Typically you'll notice on decel it will full field and charge up a lot. Also notice the amperage. Understanding how volts and amps work together is important as well.
Last edited by roadtalontsi; Nov 14, 2022 at 12:56 AM.
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Out Of Control!!
Joined: Apr 2019
Posts: 11,992
Likes: 6,825
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
voltage decrease... often normal.
Voltage range from 14.9 to 12.6 is ok based on various factors.
How low does your voltage go?
13.0V or above: no problem!
How many Amps are involved ?
30A or less: no problem!
Voltage deeping during acceleration within limits is expected so long you don't see 12.3V or lower.
OP is dealing with a case of voltage gremlins soft-crashing ESP, making his tach shaky...
When the engine to chassis GND strap is oxidized the poor battery connection can hardly sustain part of the car load during decelerations.
🤞
How low does your voltage go?
13.0V or above: no problem!
How many Amps are involved ?
30A or less: no problem!
Voltage deeping during acceleration within limits is expected so long you don't see 12.3V or lower.
OP is dealing with a case of voltage gremlins soft-crashing ESP, making his tach shaky...
When the engine to chassis GND strap is oxidized the poor battery connection can hardly sustain part of the car load during decelerations.
🤞
Super Member
Joined: Dec 2009
Posts: 826
Likes: 106
From: Sweden
2011 C63 AMG, 589hp
I swear some people just hunt and want to find problems with their cars. This is normal operation. This is a crappy 70s car that full fields the alternator all the time. It use algorithms to run the charging management system. Shuts the alternator off temporarily during acceleration. Helps with emissions and more power output. Typically you'll notice on decel it will full field and charge up a lot. Also notice the amperage. Understanding how volts and amps work together is important as well.
