yellow check engine light??
Thread Starter
Junior Member
Joined: Jun 2020
Posts: 52
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From: NYC
2021 G63 AMG - Matte Black
yellow check engine light??
I was driving home from work Friday evening and noticed the yellow check engine light illuminated (constant, not flashing). the truck was driving fine. i didn't notice any "drivability" issues. I'm bringing it to the dealership.
Has anyone experienced this before or know the potential cause(s) for the light to come on?
thanks in advance.
Has anyone experienced this before or know the potential cause(s) for the light to come on?
thanks in advance.
MBWorld Fanatic!
Joined: Oct 2019
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From: Colorado
G550
All those sensors, microcontroller ECUs, software programs, driver assistance mechanisms and high rez color displays, and the best MB can do is illuminate a yellow light to advise you of a problem.
Senior Member
Joined: May 2021
Posts: 431
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From: Washington DC
G550
I was driving home from work Friday evening and noticed the yellow check engine light illuminated (constant, not flashing). the truck was driving fine. i didn't notice any "drivability" issues. I'm bringing it to the dealership.
Has anyone experienced this before or know the potential cause(s) for the light to come on?
thanks in advance.
Has anyone experienced this before or know the potential cause(s) for the light to come on?
thanks in advance.
Thread Starter
Junior Member
Joined: Jun 2020
Posts: 52
Likes: 5
From: NYC
2021 G63 AMG - Matte Black
thanks for your input. i drove sparingly last week but didnt notice any issues other than the indicator. i dropped the truck at the dealer this morning. hopefully it's a simple fix.
Senior Member
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2025 G63MB, 2022 G63MB
it could go away on its own. it typically takes a few cycles/ starts to get reset. it happened to me and we ended up changing a few spark plugs and after a couple of visits to the dealership decided to sit it when the light came back on again and lo behold one morning it disappeared (even though the dealership clears the codes, it actually requires the vehicle to reset on its own). this all started in the first place when I was fueling one rainy day and a few droplets entered the gas tank...
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
it could go away on its own. it typically takes a few cycles/ starts to get reset. it happened to me and we ended up changing a few spark plugs and after a couple of visits to the dealership decided to sit it when the light came back on again and lo behold one morning it disappeared (even though the dealership clears the codes, it actually requires the vehicle to reset on its own). this all started in the first place when I was fueling one rainy day and a few droplets entered the gas tank...
There are supposedly additives such as ISO-Heet and Stabil-360 that can help the ethanol and gasoline recombine so that everything eventually makes it through the engine without misfires, etc. But every car manufacturer seems to advise against any fuel additives inasmuch as the additive's efficacy varies by brand, and the car manufacturers don't want to endorse any of them.
Does anyone have any experience using a fuel additive to remedy excessive water in fuel?
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'19 G63 Ed 1,'18 M5, '16 G63,'12 458 , '11 E63, Brabus SL55-K8, '10 S63, '94 E500 "Wolf", '91 560SEC
They just replacedvthe fuel pump on mine '21 4k miles. Supposedly a G550 came in right after mine with same issues.
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Thread Starter
Junior Member
Joined: Jun 2020
Posts: 52
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From: NYC
2021 G63 AMG - Matte Black
The dealer found error codes related to low coolant temp. They performed a coolant thermostat temp test and it passed twice. They cleared the error codes / check engine light and road tested the vehicle. The check engine light didn't come back on after the road test. The truck sat over night and they rechecked the system this morning. The check engine light is back on for the same error code. the dealership is opening a technical case with MB. to be continued...
MBWorld Fanatic!
Joined: Oct 2019
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Likes: 1,770
From: Colorado
G550
The dealer found error codes related to low coolant temp. They performed a coolant thermostat temp test and it passed twice. They cleared the error codes / check engine light and road tested the vehicle. The check engine light didn't come back on after the road test. The truck sat over night and they rechecked the system this morning. The check engine light is back on for the same error code. the dealership is opening a technical case with MB. to be continued...
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
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From: Colorado
G550
Thread Starter
Junior Member
Joined: Jun 2020
Posts: 52
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From: NYC
2021 G63 AMG - Matte Black
MB techs checked for loose wires, pins and connectors and determined they are not the cause. There is an internal malfunction with the thermostat itself. they are replacing the thermostat. my rep said it's a "big job". they started yesterday and will hopefully button things up today.
does anyone know what is involved in replacing the thermostat on a W463A?
does anyone know what is involved in replacing the thermostat on a W463A?
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
MB techs checked for loose wires, pins and connectors and determined they are not the cause. There is an internal malfunction with the thermostat itself. they are replacing the thermostat. my rep said it's a "big job". they started yesterday and will hopefully button things up today.
does anyone know what is involved in replacing the thermostat on a W463A?
does anyone know what is involved in replacing the thermostat on a W463A?
Thread Starter
Junior Member
Joined: Jun 2020
Posts: 52
Likes: 5
From: NYC
2021 G63 AMG - Matte Black
I picked up the truck this morning. The thermostat (177-200-08-15) was replaced. Everything seems to be buttoned up as it should be. i drove 20 miles this morning and no issues.
MBWorld Fanatic!
Joined: Oct 2019
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From: Colorado
G550
Any idea why they checked the thermostat twice and it passed, but when they replaced it the problem cleared?
MBWorld Fanatic!
Joined: Oct 2019
Posts: 5,156
Likes: 1,770
From: Colorado
G550
I think more likely the thermostat test checks that it opens at some threshold temperature, and not that it closes. This thermostat sounds as if it was stuck open, hence the low coolant temperature indication. Maybe a different tech who brought his brain to work figured this out.
