Network, generic

U055B Invalid Data Received From Special Purpose Vehicle Control Module B

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U055B concerns the second slot reserved for special purpose controllers. A receiving module gets frames from controller B, but a signal lies outside its permitted span, a counter or checksum is wrong, or the frame length does not match. No manufacturer documents U055B publicly. How freely these slots are filled shows in Deutz's engine controller for off-highway machines, which reports a timeout of its tractor-trailer bridge under U0259, the lost-communication code of slot A. On road vehicles slot B mainly matters when a conversion carries more than one add-on controller, for example separate units for warning lights and for body hydraulics. U025A is the lost-communication counterpart. Only the conversion equipment is normally affected.

Likely causes

Second add-on controller set up with wrong address or message set
Software of add-on controller B and vehicle modules not matched
Unstable supply or ground at controller B, e.g. on a shared accessory feed
Controller B internally faulty

Symptoms

  • One group of conversion functions fails while others still work
  • Fault entry in the receiving module, usually without warning lamp

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–3 h

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

Parts involved

special purpose vehicle module b

Related codes

U025AU055AU055CU055D

References: serdia.deutz.com, content.fordpro.com.