Powertrain, generic (extended)

P2CB4 Charge Air Cooler Coolant Pump B Supply Voltage Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2CB4 concerns the power feed of charge air cooler pump B rather than its command line: the pump finds its supply missing or outside the window in which it can run. No manufacturer documents P2CB4 publicly. Ford's 2024 gasoline OBD summary contains the same fault type, 1C (supply out of range), for auxiliary coolant pump B (P2B62); it is monitored all the time from 11 V battery voltage and logged after 5 s. Because the pump electronics sit inside the housing, as Bosch describes for its PCE pump, the pump measures its own supply pin and reports the result. A blown fuse, a relay with burnt contacts, a corroded ground, a damp plug or a weak battery are the usual causes; a voltage-drop test with the pump running finds hidden resistance. Without power the pump stops.

Likely causes

Blown fuse or faulty relay in the pump B feed
Corroded or loose ground connection of the pump
Moisture or corrosion at the supply pins of the connector
Weak battery or charging fault pulling the voltage down

Symptoms

  • MIL on
  • Pump B silent, charge air temperature climbs
  • Other supply-related codes may be stored at the same time

Repair estimate

DifficultyEasyDIY possible
Parts and labour€10–500
Time0.3–2 h

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

Parts involved

cac coolant pump bwiring harnessecm

Related codes

P2BC2P2CB3P2CB5P2B62U01BC

References: law.cornell.edu, fordservicecontent.com, bosch-mobility.com.