Powertrain, generic · Auxiliary emission controls

P044F AIR System Switching Valve A Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

After a cold start the secondary air pump blows fresh air into the exhaust; switching valve A is the electrically driven valve that opens this path. GM checks the valve circuit in three codes – P0412 open, P041F shorted to ground, P044F shorted to positive – while other makers use P0413/P0414 or P0412 for everything. P044F means the control circuit is shorted to positive or the coil is low-resistance: when the driver switches on, the line stays high. GM sets the code at 0.5 Ω or less to the supply (20 of 25 samples of 250 ms, above 11 V, MIL after two trips). The valve then does not open, secondary air is missing and P0411 may follow.

Likely causes

Valve coil shorted internally (low resistance)
Control wire chafed against a supply wire
Water in the connector bridging to the supply
Driver in the engine module

Symptoms

  • Check engine light on (after two trips)
  • No change in driving
  • Secondary air readiness not set, possibly P0411

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 avalve wiringengine control module

Related codes

P041FP0412P0413P0414P0411P2440

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, techtips.ie.