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U058B Invalid Data Received From Transmission Fluid Pump Module B

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

Some transmissions carry a second electrically driven oil pump with its own electronics, labelled module B, alongside or instead of a first one. Its job is to hold clutch pressure and lubrication while the combustion engine is off, so the receiving transmission or hybrid controller depends on the speed, current and fault status the pump reports. U058B is logged when those reports arrive but fail plausibility, counter or checksum checks. No manufacturer documents U058B or a pump B publicly. For pump A, Jeep replaces the in-pan electric pump on Wrangler and Grand Cherokee 4xe when lost communication U0287 appears with the MIL and limp mode. Expect start-stop or electric driving to be inhibited until the fault clears; U028A is the lost-communication partner.

Likely causes

Integrated electronics of electric pump B faulty
Pump B connector or pass-through in the transmission case wet or loose
Pump firmware and transmission controller software not compatible

Symptoms

  • Start-stop or electric drive mode unavailable
  • Transmission warning message
  • Delayed engagement after an engine restart

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,200
Time1–3 h

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

Parts involved

transmission fluid pump module b

Related codes

U028AU0588P0B0DP2797

References: static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu.