Powertrain, generic (extended)

P2E48 Hybrid/EV Electronics Coolant Pump B Overspeed

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

With P2E48 the controller sees electronics coolant pump B turning faster than commanded, without the separate dry-run test (P2E46) having fired. The usual reason is lost load, since a centrifugal pump accelerates when its impeller gets less liquid, whether from a low level, a collapsed suction hose, partial air or an impeller slipping on its shaft. A Continental patent for electric fuel pumps (US20120245819) compares pump current with voltage or speed to spot leakage or dry running without a pressure sensor. Mercedes' bulletin on pump A's P2B2A7A in the 167 series links excessive speed to leakage or a failed seal. Ford's 2024 summary combines overspeed and dry run in one fault type (B1). No manufacturer publicly documents P2E48. A false speed signal is rarer.

Likely causes

Low level or residual air in the electronics loop
Collapsed or kinked hose on the pump inlet side
Impeller slipping on the pump shaft
Implausible speed feedback from the pump electronics

Symptoms

  • MIL, sometimes with a coolant level warning
  • Louder pump noise than usual
  • Rising electronics temperatures and power limits

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–900
Time0.5–3 h

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

Parts involved

hybrid electronics coolant pump bpower electronics coolant loop

Related codes

P2E46P2E47P2E49P2C67P2E7A

References: image-ppubs.uspto.gov, static.nhtsa.gov, fordservicecontent.com, law.cornell.edu.