Powertrain, generic (extended)

P2C81 AIR System Pump Overtemperature Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2C81 reports that the secondary air pump on bank 1 has become too hot. The pump is only meant to run for a short time after a cold start, until the catalyst lights off, as Hella describes; a pump with integrated electronics can sense its own temperature and protect its motor. No manufacturer documents P2C81 publicly, so thresholds are unknown; CARB requires monitoring of secondary air delivery. Overheating points to a pump that ran far longer than planned, for example after many short cold starts in a row or with a relay stuck on (P2444), to a blocked intake filter or outlet, to worn bearings that add friction or to water inside the pump. The pump may shut itself off, so no air reaches the exhaust during warm-up and cold-start emissions climb. P2C80 is the overspeed fault, P2C82 the supply fault.

Likely causes

Pump running too long (many short cold starts, relay stuck on)
Clogged intake filter or blocked outlet path
Worn bearings or debris increasing friction
Moisture or condensate inside the pump

Symptoms

  • Check engine light
  • Pump stops early or does not run on the next cold start
  • Hot smell or grinding noise from the pump

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–700
Time0.5–2.5 h

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

Parts involved

secondary air injection pump b1wiring harnessecm

Related codes

P2C80P2C82P2444P2445P0418

References: hella.com, law.cornell.edu, patents.google.com.