Faulty switching valve solenoid with an open internal winding; Damaged, corroded or loose wiring or connector at the switching valve; Blown fuse or faulty relay supplying the valve or the secondary air circuit; Open circuit, high resistance or chafed wire between the valve and the control unit; Water or corrosion ingress into the valve or its connector; Fault inside the engine control unit driver circuit.

P0413

AIR System Switching Valve A Circuit Open.

Generic
Powertrain
Generic code
Low severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
4: AreaAuxiliary emission controls
13: FaultThe specific fault in that area

What it means

P0413 is the generic code for an open circuit in the secondary air injection (AIR) system switching valve 'A' control circuit. The engine control unit monitors the circuit that operates the valve, and it saw an open circuit (no current path) where it expected a complete one. The valve normally directs pumped air into the exhaust or exhaust ports on a cold start to help the catalyst warm up and cut emissions.

Symptoms

Engine management light on
Little or no other change in how the car drives
Possible rough or higher idle on a cold start on some models
Secondary air pump not heard running on a cold start, or running constantly
Failed emissions test or a related secondary air system code stored

Possible causes

Faulty switching valve solenoid with an open internal windinglikely
Damaged, corroded or loose wiring or connector at the switching valvelikely
Blown fuse or faulty relay supplying the valve or the secondary air circuitpossible
Open circuit, high resistance or chafed wire between the valve and the control unitpossible
Water or corrosion ingress into the valve or its connectorpossible
Fault inside the engine control unit driver circuitrare

How to diagnose

Read all stored codes and freeze frame data, and note whether other secondary air codes are present
Check for relevant technical service bulletins for the specific model and engine
Visually inspect the switching valve, its connector and the wiring for damage, corrosion, water ingress or heat damage
Check the relevant fuse and relay, following the wiring diagram for the model
Measure the valve solenoid winding resistance and compare it with the manufacturer's specification
With the connector unplugged, check for supply voltage and a good earth or control signal, and test wiring continuity back to the control unit
Use a bidirectional scan function, where supported, to command the valve and confirm it operates and the circuit responds
Check the wiring for shorts to earth or voltage and for high resistance before condemning the control unit

How to fix

Replace the switching valve if the solenoid is open circuit or fails its resistance test
Repair or replace damaged wiring, terminals or the connector, and seal against water ingress
Replace the blown fuse or faulty relay, after finding out why it failed
Repair the open circuit in the harness between the valve and the control unit
Dry and clean the connector, and fit new terminals if corrosion is found
Repair or replace the control unit only after all wiring and the valve have been proven good

Can I keep driving?

Low severity

The car can normally be driven as the secondary air system only works briefly after a cold start. Book it in soon, as the warning light will stay on and the car may fail an emissions test.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.