P0413 — Secondary Air Injection System Switching Valve A Circuit Open

OBD2 code P0413 flags a problem with the sensor and actuator circuits (secondary air injection system switching valve a circuit open). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector.

powertrain (engine/transmission)

Is it safe to drive?

Repair promptly P0413 usually does not stop the vehicle from driving if the engine otherwise runs smoothly, but the secondary air injection system may be inactive, increasing emissions and delaying catalyst warm-up. Avoid extended driving if there is severe misfire, overheating, or a flashing check engine light.

Typical symptoms

The check engine light illuminates and the OBD2 scanner reports P0413
The secondary air injection pump may run without routing air through switching valve A
No secondary air may be delivered during the commanded cold-start or fast-idle cycle
A rough idle, hesitation, or unstable idle can occur if air is leaking or is routed incorrectly
Vehicle emissions may fail inspection, and catalyst warm-up can be slower without effective secondary air

Common causes

A failed secondary air injection switching valve A with an open coil, switch, or internal connection
An open or high-resistance wire in the switching valve A control circuit
Corrosion, a loose terminal, or a pushed-back pin in the switching valve A connector
A blown fuse, defective relay, or missing power feed to the switching valve A circuit
A poor ground connection or, less commonly, a failed powertrain control module output driver

How to diagnose with an OBD scanner

Capture P0413 with an OBD2 scanner Connect an OBD2 scanner with an ELM327 adapter, or use AIScanAuto, and read stored and pending codes. Save the freeze-frame data for P0413, including engine speed, coolant temperature, and whether the secondary air pump was commanded. Do not erase the code before reviewing this information.
Inspect the valve and its wiring Locate secondary air injection switching valve A using the vehicle wiring diagram. Examine the connector and harness for corrosion, damaged insulation, pinched wires, or terminals that are not fully seated. Check the applicable fuse and relay supply.
Test power and ground under load With a multimeter, measure voltage or current at the switching valve A connector while an OBD2 scanner commands the actuator, if supported. Also verify ground continuity and voltage drop under load. An open or high-resistance circuit during the command can trigger P0413.
Isolate the switching valve Disconnect the valve and test its electrical continuity or coil resistance against service specifications. If the design uses vacuum or pressure control, inspect the control hose, source vacuum, and diaphragm. Replace the valve if it is electrically open or fails to switch.
Repair and verify operation Repair the wiring, connector, fuse, relay, ground, or switching valve as testing identifies. Clear P0413 with the scanner, then perform a supported actuator test. Confirm that switching valve A moves, the pump delivers air when commanded, and P0413 does not return.

Approximate repair cost

A typical independent-shop estimate for diagnosing and repairing P0413 is USD 180-650, depending on valve accessibility, parts availability, and whether wiring or a relay also requires service. Diagnostic labor alone may be USD 100-180. These figures are estimates and vary by region.

Common questions

What does OBD2 code P0413 mean?

P0413 means the control circuit for secondary air injection switching valve A is open. The fault can come from the valve itself, damaged wiring, a poor connector, or an interrupted power or ground supply.

Can I safely drive my vehicle with P0413 stored?

Driving is generally possible if the engine idles and runs normally, but the emissions system may not operate correctly. Arrange prompt repair, and stop driving if the check engine light flashes or the engine overheats or misfires severely.

Does P0413 always mean the secondary air injection pump is defective?

No. P0413 specifically identifies an open switching valve A circuit. The pump may function properly while a wire, connector, relay, ground, or switching valve causes the circuit failure.

What should a technician check before replacing parts for P0413?

The technician should verify the freeze frame, inspect the connector and harness, test fuse and relay power, measure voltage and ground, and check the valve electrically. Replacing the valve before completing these tests may leave P0413 unchanged.

When your engine control unit detects a break in the electrical circuit that operates the secondary air injection system's switching valve, it logs trouble code P0413. The "circuit open" designation means that no electrical current can flow through a section of wiring that the module expects to be complete. This is different from a short circuit — here, the problem is an interrupted path, like a wire that has snapped or a connector that has come loose. Because the secondary air injection system plays a role in reducing emissions during cold starts, the ECU flags this condition in the powertrain category and triggers the Check Engine light.

The secondary air injection system itself varies between manufacturers, but most setups include an electric air pump, one-way check valves, and at least one electronically commanded switching valve or solenoid. The ECU activates this system briefly after a cold start to inject fresh air into the exhaust stream, helping to speed up catalyst light-off and lower raw emissions. When the switching valve is commanded to open but the control circuit shows no sign of current flow, the ECU knows something is wrong with that circuit. After monitoring the condition through enough drive cycles to rule out a fleeting glitch, it stores P0413. The freeze frame data saved alongside the code is particularly useful — it records engine RPM, load, temperature, and vehicle speed the instant the fault was detected, giving you a precise starting point for troubleshooting.

There are several ways an open circuit can develop. A broken wire somewhere along the harness is the most common culprit, especially in areas exposed to heat, vibration, or physical movement. Connector problems rank second: a connector that has backed out of its housing, a pin that has pushed in too far, or corrosion eating away at the metal contacts will all break the electrical path. A blown fuse that feeds the switching valve circuit is another frequent cause — without power, the circuit cannot complete. An internally failed switching valve can also present as an open circuit from the ECU's perspective. Less commonly, a poor ground connection or a fault in the control module itself can mimic an open circuit. Wiring that has abraded through its insulation or been chewed by rodents may develop intermittent opens that only appear under certain conditions.

The Check Engine light is the most obvious sign that P0413 has been set. Beyond that, you may notice the secondary air injection system operating intermittently or not at all — you might hear the air pump running but feel no change in performance, or hear nothing when it should be active. Some vehicles enter a limited-performance limp mode if the ECU detects a problem in this system, while others simply continue driving normally aside from the illuminated warning light. In cases where the engine runs less efficiently due to the system being disabled, you may see a modest increase in fuel consumption. Most of the time, however, the car remains drivable and you may not notice any driveability issue at all until you scan for codes.

Symptoms of P0413

Check Engine light is illuminated
Secondary air injection system does not activate or activates intermittently
Possible limp mode or reduced engine performance on some vehicles
Slightly elevated fuel consumption in some cases
No other drivability symptoms in many applications

Common Causes of P0413

Broken or severed wire in the secondary air injection switching valve harness
Blown fuse feeding the switching valve control circuit
Internally open or failed secondary air injection switching valve
Connector unplugged, pin backed out, or heavy corrosion on terminals
Corroded, loose, or otherwise damaged wiring connector
Open or intermittent wiring short of a full break in the circuit
Poor ground connection for the circuit or control module driver fault

How to Diagnose P0413

Connect an OBD2 scanner, confirm P0413 is stored, and record the freeze frame data — this snapshot shows engine conditions at the moment the fault occurred and tells you whether it happened at idle, under load, or during a cold start.
Pull any additional stored codes. Related trouble codes often point to the root cause — for example, a short circuit in the same circuit may produce a different but related code.
Check for manufacturer technical service bulletins (TSB) for your specific make and model. Many emission-related codes like P0413 have known factory fixes, software updates, or service campaigns documented by the manufacturer.
Visually inspect the wiring harness and connectors at the secondary air injection switching valve. Look for broken insulation, chafing, melted wire, corrosion buildup, or pins that are bent, pushed out, or covered in greenish oxidation.
Perform a continuity test on the switching valve circuit end-to-end. With the connector unplugged, check resistance from one end of the harness to the other — an open circuit will show infinite resistance. Wiggle the harness while measuring to expose intermittent faults.
Measure reference voltage and ground at the component connector with the harness plugged in. The ECU should show near-battery voltage on the power feed and a solid ground on the ground side. A missing voltage reading confirms an open somewhere upstream.
Clear P0413, complete a full drive cycle including conditions similar to those in the freeze frame, and re-scan to verify the code does not return.

Repair Options for P0413

If the inspection reveals damaged wiring, repairing or replacing the affected section of harness and cleaning or replacing corroded connectors typically costs between $80 and $250 including labor. When the switching valve itself has failed internally, replacement of the faulty sensor or actuator runs $150 to $500 for parts and installation. If diagnostics point to a problem within the control module or its driver circuit, module-level repair or replacement is a more involved fix, generally ranging from $300 to $1,000 depending on whether the module can be rebuilt or must be replaced outright.

How Much Does It Cost to Fix P0413?

The total bill hinges entirely on what component caused the open circuit. At independent shop rates in the United States, here is what you can expect for the most common repair scenarios:

Wiring repair or connector replacement: $80–$250
Control module diagnosis and repair: $300–$1,000
Secondary air injection switching valve replacement: $150–$500

In most cases, fixing P0413 falls somewhere between $80 and $250 if the problem is a simple wiring or connector issue. The $300–$1,000 scenario is reserved for control module faults, which are far less common. Doing a thorough diagnosis before purchasing any parts is the best way to avoid paying for expensive components you do not need.

Can You Drive with P0413?

Yes — in the majority of vehicles, P0413 does not prevent the car from driving. You will likely see reduced emissions efficiency and possibly a minor decrease in performance depending on your application. Some cars trigger a limp-home mode, but this varies by manufacturer and model. Treat the issue as a priority if you experience stalling, hard starting, or warnings affecting the brakes or steering, as these indicate a more serious condition that should be addressed immediately.