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Service bulletin Circular 34K1

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10241185
Published by NHTSA2023-09-01
Manufacturer's numberCircular 34K1
Manufacturer's date2023-08-03
NHTSA componentPOWER TRAIN; ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)

NHTSA's summary

Volkswagen is providing updated transmission control module (TCM) software to enhance an in-vehicle alert should a problem arise within the auxiliary hydraulic pump. Additionally, if a specific fault is found after the software is updated, a repair will be made to the transmission.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Electrical system, Transmission and driveline, Automatic transmission, Transmission control module

Vehicles listed
VOLKSWAGEN GOLF R2018

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
Dealer34K1_REV12023-12-06. Service bulletin. "Transmission Control Module (TCM) Software - Updated repair steps after software update is completed. Added example photos of transmission damage. Added Canadian TSB number to reference if car returns with fault."
Circ34K1_REV12023-12-06. Service bulletin. "Transmission Control Module (TCM) Software - Updated repair steps after software update is completed. Added example photos of transmission damage. Added Canadian TSB number to reference if car returns with fault."
Dealer 34K12023-09-01. Service bulletin. Dealer Letter to announce Repair Available - Service Action 34K1 / TCM Software
V3718022033975112023-07-10. Service bulletin. Automatic Transmission Fluid Requirements
Dealer34J734L92022-02-04. Service bulletin. Replace the gear shift cover chrome trim frame.
Circ_34J734L92022-02-04. Service bulletin. Replace the gear shift cover chrome trim frame.
TT 34 21 012021-07-02. Service bulletin. Reverse gear function note.
18VWUSMN1126192019-12-06. Service bulletin. "Additional Maintenance Items section: ""Transmission, Automatic (non-DSG): Change fluid and filter every 80K miles"" REMOVED: ""and filter"""