Powertrain, generic · Auxiliary emission controls

P0416 AIR System Switching Valve B Circuit Open

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

The switching valve is the electrically driven valve of this path – a solenoid valve, or on Pierburg/VW systems an electric changeover valve that applies vacuum to the pneumatic combination valve; valve A serves the first path or bank 1, valve B the second. P0416 means the control circuit of valve B is open – the module does not see the expected level with its driver switched off. On Subaru's two-valve system valve B serves bank 2; the bulletin advises checking the valve of the other bank too, because a shared supply can be the cause. The valve stays shut and that bank gets no secondary air.

Likely causes

Wire or connector to valve B open
Coil of valve B burnt out
Shared supply of both valves faulty
Engine module

Symptoms

  • Check engine light on
  • Secondary air inactive on bank 2
  • Secondary air readiness not set (emission test)
  • Driving normal

Repair estimate

DifficultyEasyDIY possible
Parts and labour€30–300
Time0.3–1.5 h

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

Parts involved

air switching valve bair combination valvevalve wiringengine control module

Related codes

P0415P0417P0413P2442P2443

References: static.nhtsa.gov, techtips.ie, law.cornell.edu.