Mercedes-Benz AMG GLC43 2023–2026 — technical service bulletin
Bulletin LI20.00-P-076708 · NHTSA communication 11023049 · issued Sep 9, 2025
Technical service bulletin
communication type
Engine
component
2023–2026
model years
21
vehicle entries
Official summary
Complaint Check engine lamp activated, coolant warning message, and engine fan running at full speed. Below fault codes stored in N127 PTCU related to LIN network components. U063200, U063287, U02A900, U02A987, U0698E4, U0698E5, U02C800, U02C887, U063B00, U063B87 Cause PTCU software, or physical layer fault in LIN bus circuit Remedy Model 254 (with version 22A) -Update software of PTCU N127 -Cleared fault codes and check vehicle operation Model 254 after update or with PTCU version later than 22A, or Model 167 -Check connections at all LIN bus components connected to N127 PTCU for damage, corr
Vehicles covered
- 2024 Mercedes-Benz AMG GLC43
- 2024 Mercedes-Benz AMG GLC43 4MATIC Coupe
- 2025 Mercedes-Benz AMG GLC43 4MATIC Coupe
- 2024 Mercedes-Benz AMG GLC63 S E
- 2025 Mercedes-Benz AMG GLC63 S E
- 2025 Mercedes-Benz AMG GLC63 S E 4MATIC+ Coupe
- 2023 Mercedes-Benz GLC 300
- 2024 Mercedes-Benz GLC 300
- 2025 Mercedes-Benz GLC 300
- 2026 Mercedes-Benz GLC 300
- 2023 Mercedes-Benz GLC 300 4MATIC
- 2024 Mercedes-Benz GLC 300 4MATIC
- 2025 Mercedes-Benz GLC 300 4MATIC
- 2026 Mercedes-Benz GLC 300 4MATIC
- 2024 Mercedes-Benz GLC 300 4MATIC Coupe
- 2025 Mercedes-Benz GLC 300 4MATIC Coupe
- 2026 Mercedes-Benz GLC 300 4MATIC Coupe
- 2024 Mercedes-Benz GLC 300 Coupe
- 2025 Mercedes-Benz GLC 350 E 4MATIC
- 2024 Mercedes-Benz GLE 350 4MATIC
- 2025 Mercedes-Benz GLE 350 4MATIC
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.