Powertrain, generic (extended)

P2E43 Hybrid/EV Electronics Coolant Pump B Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2E43 means the command signal of electronics coolant pump B sits too low, typically because the line has contact with ground or the output stage cannot drive it up. On PWM-controlled pumps this usually stops the pump outright. Pierburg's CWA pumps, a widespread design, read a duty cycle of 0 to 1 % as stop and pull their PWM input to ground through 10 kΩ, so a grounded line leaves the rotor standing. Ford's 2024 summary treats circuit low (fault type 11) on its auxiliary pumps as a report from the smart driver, checked over 5 s at a battery voltage of at least 11 V. GM's 2016 hybrid tables fold grounded, voltage-shorted and open lines into a single pump A code, P0CE9. No manufacturer publicly documents P2E43. Chafed insulation and wet connectors are usual finds. The high-side code is P2E44, pump A's version P0CEB.

Likely causes

Control wire chafed through and shorted to ground
Moisture or corrosion bridging pins in the pump connector
Shorted input stage inside pump B
Output stage of the module stuck low

Symptoms

  • Pump B stops, electronics coolant heats up
  • MIL with hybrid or drive system message
  • Limited power or charging rate under load

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–700
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

P2E44P2E41P2E45P0CEB

References: tecomotive.com, tecomotive.com, fordservicecontent.com, gsi.ext.gm.com.