Network, generic

U0254 Lost Communication With Remote Start Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

A remote start module runs the engine from a key fob or app so the cabin can be heated or cooled before departure. GM's list for the 2011 Saab 9-5 treats it as a network node of its own under U0254. Subaru documents the code for 2020 Legacy and Outback models with the genuine accessory Remote Engine Starter: the central gateway stored U0254 during an all-systems check because of a software interface mismatch between gateway and starter, although the accessory worked normally. The bulletin allows ignoring the code on its own, and later replacement starter units carry revised U0254 logic (15-258-19, revised as 15-258-19R). With a real fault the starter is unpowered, unplugged or defective, so remote start fails while normal driving is unaffected. Corrupt frames from it are U0555.

Likely causes

Software interface mismatch between gateway and accessory starter (Subaru), no real fault
Poor installation, loose connector or missing supply of an accessory or aftermarket starter
Starter removed or disconnected while the vehicle configuration still expects it
Internal failure of the remote start module

Symptoms

  • Remote start does not work or stops after a short time
  • Code found only during a full system scan, no other complaint

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–500
Time0.2–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

remote start modulevehicle bus wiring

Related codes

U0555U0146U0258U0167

References: static.nhtsa.gov, static.nhtsa.gov, saabwisonline.com.