Powertrain, generic (extended)

P2CA2 Charge Air Cooler Coolant Pump Sense Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2CA2 is set when the return wire from the intercooler pump sits below its valid range for longer than allowed. Insulation worn through against the body, water in the plug, or pump electronics that keep pulling the line down are the usual suspects. The last case is tricky: pumps working on the principle in Pierburg's patent US8392060B2 report a fault by grounding the line for a coded duration, so a line that never comes back up looks the same as a pump stuck in its error state, and a real pump defect may stand behind the code. MACS stresses that electric water pumps work with a PWM input plus a feedback signal, so both should be scoped side by side. No manufacturer documents P2CA2 publicly; CARB requires the circuit check. P2CA1 is the high case.

Likely causes

Feedback wire chafed against body or engine ground
Pump electronics holding the line low because of an internal fault
Moisture or corrosion bridging pins in the pump connector

Symptoms

  • MIL on
  • Engine power limited when charge air temperature rises
  • Code may appear together with pump speed or performance codes

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–700
Time0.5–3 h

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

Parts involved

cac coolant pumpwiring harnessecm

Related codes

P2CA1P2CA3P023BP026EU05AA

References: law.cornell.edu, patents.google.com, macsw.org.