LI83.20-P-072178

G-FACELIFT 2018: Noises Coming From Driver's Side Footwell
Topic number
LI83.20-P-072178
Version
1
Function group
83.20 Heating
Date
12-18-2020
Validity
Model 463 as of model year 2019 (as of code XZ8)
Reason for change
Recommended repair has been changed based on new
technical findings
Reason for block
Complaint:
The customer complains that when the ignition is switched on, pulsating buzzing noises which fluctuate in volume can
be heard coming from the area of the instrument panel or the driver's footwell.
Note: A quiet, constant buzzing noise corresponds to the series product configuration.
Attachments
File
Description
Soundfile Noise Driverseat.MP3
Sound file of interior
Cause:
The listed complaints may be originating from the circulation pump in the heating circuit.
The cause may be air in the low-pressure heating circuit, which can generate noise when there is flow through the circulation pump.
Remedy:
Check whether the noise is coming from the circulation pump (M13/5). To do so, remove the front left wheel well liner.
If the noise is being caused by the circulation pump, replacing the part would not be a productive solution.
To resolve the issue, the system needs to be vented by driving the vehicle carefully at a constant engine speed above
3000 rpm for a period of at least 30 minutes.
When doing so, it is important that the air conditioning is completely switched off.
Note: The circulation pump runs when the air conditioning is switched on and will prevent self-venting of the cooling
system.
Symptoms
12-18-2020 3:44 PM
© Copyright Mercedes-Benz AG
JKANTAR
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Body / Air conditioning / Stationary heater/auxiliary heater / Noise
Body / Air conditioning / Heater / Noise
Body / Air conditioning / Air conditioning / Noise
Operation numbers/damage codes
Op. no.
Operation text
Time
Damage
code
Note
83408 36
Heating system circulation pump noise
Validity
Vehicle
Engine
Transmission
G (463) - 463.210
*
*
G (463) - 463.260
*
*
G (463) - 463.261
*
*
G (463) - 463.276
*
*
G (463) - 463.277
*
*
G (463) - 463.349
*
*
G (463) - 463.350
*
*
12-18-2020 3:44 PM
© Copyright Mercedes-Benz AG
JKANTAR
Page 2/2