P0419 on Toyota
Secondary Air Injection System Relay "B" Circuit
P0419 on Toyota vehicles indicates secondary air injection system relay "b" circuit. Au7o has documented this code across 1 Toyota model — most commonly on 4Runner. This code indicates the PCM detected a fault in the control circuit for secondary air injection relay 'B'. This relay powers the secondary air injection pump, which forces fresh air into the exhaust during cold starts to help the catalytic converter reach operating temperature and reduce emissions. A circuit fault here keeps the system from operating correctly, mainly affecting cold-start emissions. It generally triggers the check engine light without major performance issues. Typical repair costs on Toyota range from $900 to $3,000, depending on the specific model and root cause.
Common Causes of P0419
- •Faulty secondary air injection relay
- •Open or shorted wiring in the relay control circuit
- •Corroded or loose relay connector
- •Loss of power or ground to the relay
- •Failed secondary air injection pump drawing abnormal current
- •Failing PCM (less common)
P0419 on Toyota by Model
Toyota 4Runner(1 issue)
- Secondary Air Injection Pump/Valve Failure Triggering Limp Mode on 4.7L V82005-2009
The 4.7L 2UZ-FE V8 used in later 4th-generation 4Runners is known for secondary air injection system failures involving the air pump and switching valves. When the system sticks or fails electrically, the truck may illuminate the check engine light and enter reduced-power or limp mode. This problem is widely documented across Toyota V8 trucks and SUVs of the era and can be very expensive when repaired with OEM components.
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What does P0419 mean on Toyota?▼
P0419 stands for "Secondary Air Injection System Relay "B" Circuit." This code indicates the PCM detected a fault in the control circuit for secondary air injection relay 'B'. This relay powers the secondary air injection pump, which forces fresh air into the exhaust during cold starts to help the catalytic converter reach operating temperature and reduce emissions. A circuit fault here keeps the system from operating correctly, mainly affecting cold-start emissions. It generally triggers the check engine light without major performance issues. On Toyota specifically, this code is documented across 1 model.
What causes P0419 on Toyota vehicles?▼
Common causes on Toyota: Faulty secondary air injection relay, Open or shorted wiring in the relay control circuit, Corroded or loose relay connector, Loss of power or ground to the relay, Failed secondary air injection pump drawing abnormal current. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0419 on a Toyota?▼
Repair costs on Toyota range from $900 to $3,000, depending on the specific model and root cause.
Which Toyota models have P0419 documented?▼
Au7o has documented P0419 on 1 Toyota model: 4Runner.