Powertrain, generic (extended)

P2B9D Coolant Pump A Supply Voltage Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2B9D means the power feed of coolant pump A is outside its usable range, as opposed to the command line covered by P2600 to P2603. Ford names it in the 2024 gasoline OBD summary as fault type 1C (feed voltage outside its window) of the cabin-heating auxiliary pump, monitored all the time from 11 V battery voltage with a 5-second window. Since these pumps carry their own electronics, they measure the voltage on their supply pin and report the deviation. Look for a blown fuse, a relay with burnt contacts, corrosion in the plug, a bad ground strap or a weak battery; a voltage-drop test with the pump running finds hidden resistance best. CARB 13 CCR 1968.2 (e)(15) demands monitoring of such outputs. The same fault on pump B is P2B62, on pump D P2B69.

Likely causes

Blown fuse or faulty relay in the pump supply
Corroded connector or poor ground at the pump
Weak battery or charging system voltage too low
Chafed or broken supply wire

Symptoms

  • Cabin heat weak or missing
  • Check engine light
  • Fault comes and goes with battery condition or electrical load

Repair estimate

DifficultyMediumDIY possible
Parts and labour€10–400
Time0.3–2 h

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

Parts involved

coolant pump awiring harnessecm

Related codes

P2B9CP2B9EP2B62P2B69P26F7P2600

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