Network, generic

U0549 Invalid Data Received From Remote Accessory Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

No manufacturer explains in public what the remote accessory module is; the term shows up only in code lists, together with its lost-communication partner U0248. Going by the name, it is a body-side unit controlling accessories away from the main controllers, and it is distinct from the accessory protocol interface module covered by U0554. GM's Saab 9-5 documentation describes the supervision behind such codes: receivers watch for expected signals, substitute defaults when a signal is not valid and set a code against the sender, and its code list splits invalid data into subtypes such as wrong message counter, checksum error or implausible value. U0549 follows that scheme for this module. What stops working depends on the vehicle; driving is not affected.

Likely causes

Remote accessory module internally faulty
Retrofitted or upfitter equipment disturbing the module's data
Low battery voltage or power interruption while the module was active

Symptoms

  • An accessory function controlled by this module does not work
  • Code stored without noticeable effect

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–600
Time0.5–3 h

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

Parts involved

remote accessory module

Related codes

U0248U0554

References: saabwisonline.com, saabwisonline.com.