Powertrain, generic · Auxiliary emission controls

P041F AIR System Switching Valve A Circuit Low

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. P041F means the control circuit is shorted to ground: GM checks with the driver switched off and sets the code at 0.5 Ω or less to ground (20 of 25 samples of 250 ms, above 11 V, MIL after two trips). The valve is then energised and open although not commanded; P0411 or P2440 may follow.

Likely causes

Control wire chafed against ground
Water or corrosion in the valve connector
Valve coil shorted to its housing
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

P044FP0412P0413P0414P2440P0411

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