Tesla, Inc.
Service Bulletin

SB-24-21-002
December 11, 2024

Improve GNSS Performance For HW4
Vehicles With 1st Generation Antenna

Classification

Section/Group

Mobile Service

Configuration

Campaign Bulletin

21 - Infotainment

Can Perform (where
permitted)

HW4, 1st Generation
GNSS Antenna

Model

Model Year

Country/Region

Build Location

Model S

2021+

Fremont

Model X

2021+

North America, Europe, Middle
East

The model(s) and model year(s) listed are a general approximation of the affected VIN list. Refer to the VIN/Bulletin Tracker or Customer/Vehicle profile to determine
applicability of this bulletin for a particular vehicle.

Campaign Bulletin: This campaign bulletin addresses a non-safety-related condition and provides recommended technical
diagnosis and repair procedures. Apply this procedure to the applicable vehicles.

Condition
Some Model S and Model X vehicles with 1st Generation Global Navigation Satellite System (GNSS) antennas might
suffer from lower-than-expected navigation signal strength under certain circumstances.

Correction
Perform USB device troubleshooting to determine whether aftermarket USB devices are interfering with navigation
signals. If necessary, replace the GNSS antenna and rear view mirror upper cover with updated parts. Perform
extended GNSS diagnostics on the vehicle if the initial remedies are ineffective.

Correction Description

Correction

Time

Vehicle GNSS Signal Strength Readings Are Within Specification; SB-24-21-002

S012421002

0.42

Perform USB Device Troubleshooting To Address SB-24-21-002

S022421002

0.42

Replace GNSS Antenna To Address SB-24-21-002

S032421002

0.54

Replace GNSS Antenna And Rear View Mirror Upper Cover To Address SB-24-21-002

S042421002

0.54

Perform USB Device Troubleshooting; Replace GNSS Antenna To Address SB-24-21-002

S052421002

0.96

Perform USB Device Troubleshooting; Replace GNSS Antenna And Rear View Mirror
Upper Cover To Address SB-21-002

S062421002

0.96

Part Number
If Necessary 1920001-00-B

Description

Quantity

ASSEMBLY GNSS MILKWEED ANTENNA

1

1587847-00-E

For Model S
REARVIEW MIRROR UPPER COVER

1

1632802-00-E

For Model X
ASSEMBLY REAR VIEW MIRROR UPPER COVER

1

These part numbers were current at the time of publication. Use the revisions listed or later, unless
otherwise specified in the Parts Catalog.

Page 1 of 4

SB-24-21-002
_

Check for Aftermarket USB Devices
Check the center console and glove box for any aftermarket USB devices that are being stored. Also check whether
aftermarket USB devices are plugged into the center console and glove box USB ports (Figures 1–3).
NOTE: Tesla USB devices, such as the Tesla USB drive (Figure 4) or Tesla Solid State Drive (Figure 5), have
minimal effect on GNSS performance and can be ignored.

Figure 1 – Center console front USB ports

Figure 2 – Center Console rear USB ports

Figure 3 – Glove box USB ports; Model X shown, Model S similar

Figure 4

Figure 5

•

If no aftermarket USB devices are plugged into the center console and glove box USB ports, and there are no
disconnected aftermarket USB devices stored inside of the center console and glove box, USB devices are
not currently affecting navigation performance on this vehicle. Skip to the “Replace GNSS Antenna and (If
Necessary) Rear View Mirror Upper Cover” section.

•

If aftermarket USB device(s) are plugged into the center console USB ports, or if there are disconnected
aftermarket USB devices stored in the center console or glove box, continue to “Troubleshoot USB Devices”.
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SB-24-21-002
_

Troubleshoot USB Devices
The procedure described in this section determines whether the customer’s aftermarket USB device(s) are emitting
electromagnetic energy that is negatively impacting navigation signal reception strength.
1. Under a clear sky, park the vehicle where the view of the sky is unobstructed by tall structures such as buildings
or trees.
2. Plug all of the customer’s USB devices into the center console USB port(s).
NOTE: Use only the customer’s USB devices. Do not troubleshoot with USB devices that were not found in
the customer’s vehicle.
3. Enable Service Mode (refer to Service Manual procedure 00050100; Model S, Model X).
4. In the Service Mode menu, touch Driver Assist > Cameras, and in the “Carrier/Noise” section of the “GNSS”
panel, monitor the GPS, BeiDou, and Galileo signal strength readings (Figure 6).

Figure 6
•

If the GPS, BeiDou, and Galileo signal strength readings are all “40” or greater, the condition described by this
bulletin is not the issue. Use correction code S012421002, and then continue diagnosis if necessary.

•

If any of the GPS, BeiDou, or Galileo signal strength readings are less than “40”, disconnect the USB
device(s) from the vehicle while continuing to monitor the GNSS signal strength readings.
o

If the GPS, BeiDou, and Galileo signal strength readings are all “40” or greater after disconnecting the
USB device(s), discontinue this procedure and use correction code S022421002.
NOTE: Upon return of the vehicle to the customer, inform them that Tesla confirmed that the USB
device(s) used in the vehicle were interfering with vehicle navigation signal reception. Advise them to
disconnect the device(s) when using navigation or Autopilot features if they wish to avoid performance
issues with those features.

o

If any of the GPS, BeiDou, or Galileo signal strength readings are still less than “40”, continue to the
“Replace GNSS Antenna and (If Necessary) Rear View Mirror Upper Cover” section.

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SB-24-21-002
_

Replace GNSS Antenna and (If Necessary) Rear View Mirror Upper Cover
Newer versions of the GNSS antenna and rear view mirror upper cover are available. These updated parts are more
resistant to electromagnetic interference and may improve vehicle navigation signal strength. If USB device
troubleshooting was not performed (i.e., the vehicle did not have any aftermarket USB devices in use or in storage), or
if the troubleshooting did not address low navigation signal strength issues, perform the following steps:
1. Replace the GNSS antenna with an updated part (see parts table on page 1) (refer to Service Manual procedure
21320102; Model S, Model X).
NOTE: Replace the antenna even if GNSS signal strength readings have not been tested yet.
NOTE: During disassembly, check the rear view mirror upper cover for the presence of metal shielding
(Figure 7).

Metal shielding

Figure 7
•

If the rear view mirror upper cover has metal shielding, install the same upper cover during
reassembly.

•

If the rear view mirror upper cover does not have metal shielding, replace the upper cover with an
updated part (see parts table on page 1).

2. With all USB devices disconnected, obtain GNSS signal strength readings (Figure 6) by performing steps 1, 3,
and 4 in “Troubleshoot USB Devices”.
•

If the GPS, BeiDou, and Galileo signal strength readings are all “40” or greater, discontinue this procedure
and use correction code S032421002, S042421002, S052421002, or S062421002.
NOTE: Inform the customer that aftermarket USB devices may interfere with vehicle navigation signal
reception. Advise them that disconnecting their device(s) may be necessary when using navigation or
Autopilot features if they wish to avoid performance issues with those features.

•

If any of the GPS, BeiDou, or Galileo signal strength readings are still less than “40”, extended GNSS
diagnostics is required. Use correction code S032421002, S042421002, S052421002, or S062421002, and
then refer to Toolbox article 7032500. Track any additional work in a separate service activity, using correction
code 00100004.

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SB-24-21-002
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