Powertrain, generic (extended)

P2CB0 Charge Air Cooler Coolant Pump B Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P2CB0 flags that charge air cooler pump B is electrically in order but does not work the way its operating data say it should. No manufacturer documents the code publicly. GM shows how the same check runs on pump A (P026E) in its 2025 diesel table 25OBDG04B: the motor phase current expected for the measured pump speed is compared with the actual current, and an error above 5 A for more than 5 s, with the pump above 1,000 rpm and coolant between 10 and 126 °C, sets the code after 16 failures in 20 samples – Type A, MIL on the first trip. Bosch describes such pumps as brushless units whose own circuit board handles motor control and diagnosis. Worn bearings, a damaged impeller, a restricted loop or low coolant are typical. Pure over- or underspeed has its own codes, P2CB1 and P2CB2.

Likely causes

Low coolant level or air pockets in the charge air cooler loop
Worn bearing or damaged impeller in pump B
Kinked hose, clogged cooler or debris restricting flow

Symptoms

  • MIL on
  • Charge air temperature higher than normal, power reduced
  • Unusual whining or rattling from the pump

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–800
Time0.5–3 h

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

Parts involved

cac coolant pump bcac coolant loopecm

Related codes

P026EP2CB1P2CB2P2CB3P2CAD

References: law.cornell.edu, gsi.ext.gm.com, bosch-mobility.com.