MERCEDES-BENZ · 2025-09-09
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, corrosion, or poor connection -Check wiring between LIN bus components and N127 for damage or chaffing -Inspect intermediate connections between LIN bus components and N127 for damage, corrosion, or poor…