Powertrain, generic · Auxiliary emission controls

P0410 AIR System A

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

After a cold start the secondary air (AIR) pump blows fresh air behind the exhaust valves so that unburnt fuel burns off and the catalyst heats up faster; a shut-off valve opens the path and stops exhaust from flowing back. P0410 is the general function code for secondary air system A. Many Bosch-managed engines check it passively: with the pump running, the front oxygen sensor must read lean or the fuel control must react; Pierburg lists P0410 as no lean signal, i.e. no air detected. Saab's Motronic 900, by contrast, uses it for too much air. GM's systems with a pressure sensor use P0411 and P2440 ff instead. The check runs once per trip after a cold start; driving is unaffected.

Likely causes

Secondary air pump failed (water ingress, seized)
Combination or shut-off valve carboned up or stuck
Vacuum hose or electric changeover valve leaking or faulty
Pump relay or fuse faulty
Air ducts in the head carboned up or hose off

Symptoms

  • Check engine light on
  • Secondary air readiness not set (emission test)
  • Pump silent after a cold start, or unusually loud
  • Driving normal, higher cold-start emissions

Repair estimate

DifficultyMediumDIY possible
Parts and labour€80–900
Time0.5–3 h

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

What to check first

  1. Check pump operation at cold start
  2. Check fuse and relay
  3. Inspect check valve and hoses

Parts involved

secondary air pumpair combination valveair pump relayfront oxygen sensor

Related codes

P0411P0412P0418P0491P2440P2444

References: techtips.ie, saabwisonline.com, saabwisonline.com, law.cornell.edu.