Powertrain, generic (extended)

P2B64 Coolant Pump B Control Module Overtemperature

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2B64 reports that the electronics built into coolant pump B have become too hot and the pump has protected itself, usually by derating or shutting down. In Ford's 2024 gasoline OBD summary it is failure type 98 (system over temperature) of the pump B check under P261A, monitored continuously. Such overheating mostly follows a lack of cooling for the pump's own driver: coolant missing or full of air, a motor labouring against a sticking impeller, very hot surroundings near turbo or exhaust, or an ageing power stage. Because these pumps shed the heat of their electronics into the coolant they move, level and bleeding come first in diagnosis. P2B63 (stalled) and P2B65 (air) often share the root cause. Pump A has P2B9E, pump D P2B6B.

Likely causes

Coolant level low or air at the pump, so the electronics are not cooled
Sluggish impeller raises motor current and heat
Power stage inside the pump degraded
Damaged heat shield or high radiant heat at the mounting point

Symptoms

  • Warning lamp with stored code
  • Pump stops intermittently, often after long or hot drives
  • Reduced cooling of the served component

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–900
Time0.5–4 h

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

Parts involved

coolant pump bwiring harnessecm

Related codes

P2B62P2B63P2B65P2B9EP2B6B

References: fordservicecontent.com, law.cornell.edu.