P2445 on 2005-2009 Toyota 4Runner: Secondary Air Pump Stuck Off Fixes

What's Unique About the 2005-2009 Toyota 4RUNNER

The 4.7L V8 (2UZ-FE) engine used in the 4th generation 4Runner has a well-documented design flaw with its SAI system. The system's foam air filter is known to dry-rot and disintegrate, with the debris being sucked into the pump. This debris can destroy the pump's impeller and then travel downstream, clogging the air switching valves. Because the pump and valves are located under the intake manifold, replacement is labor-intensive and expensive. 🎬 Watch this step-by-step guide to replacing the pump and valves. While Toyota issued warranty extensions (not recalls) for the same issue on Tundra and Sequoia models with the same engine, 4Runner and Lexus GX470 owners were not included, which is a major point of frustration.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is on
• VSC and TRAC OFF lights are illuminated
• Vehicle enters 'limp mode' (fail-safe mode) with drastically reduced power and acceleration.
• Loud vacuum cleaner-like noise from the engine bay for about 30-60 seconds on a cold start (indicates a failing pump before it dies completely).
• After the pump fails, the vacuum cleaner noise will be absent on cold starts.

Most Likely Causes

1. Failed Secondary Air Injection Pump 🔴 High Probability → Shop Secondary Air Injection Pump The pump's foam filter is known to disintegrate over time, getting sucked into the pump, breaking the impeller blades, and causing the motor to seize. Moisture can also enter the pump housing, causing corrosion and failure.
   How to confirm: Listen for the pump running on a cold start. If there's no sound, check the 50A SAI fuse and relay in the under-hood fuse box. If those are good, use a scan tool to command the pump on and check for voltage at the pump's connector. Voltage with no pump activity confirms a failed pump. 🎬 Watch a mechanic diagnose a P2445 code on the 4.7L V8. Debris in the housing is also a strong indicator.
   Typical fix: Replace the secondary air injection pump assembly. Due to the high cost and labor, many owners also replace the air switching valves and gaskets at the same time as a preventative measure.
   Est. part cost: $500-$1200
2. Failed Air Switching Valve(s) 🟡 Medium Probability The same foam debris that kills the pump can travel downstream and cause the valves to stick open or closed. While other codes (P2440-P2443) point more directly to valves, a stuck valve can prevent proper system operation, contributing to the P2445 code.
   How to confirm: Use a bi-directional scan tool to command the valves to open and close. Listen for an audible click and observe pressure changes in the system data. Visual inspection during pump replacement may reveal debris in the valve ports.
   Typical fix: Replace the faulty air switching valve(s). They are located under the intake manifold and are often replaced along with the pump.
   Est. part cost: $200-$400 per valve
3. Blown SAI Fuse or Failed Relay ⚪ Low Probability A failing pump motor drawing excessive current can cause the main 50A fuse to blow as a protective measure. This is often a symptom of a seized pump, not the root cause.
   How to confirm: Locate and inspect the fuse and relay for the SAI system in the under-hood fuse box. Test with a multimeter or swap with a known-good relay.
   Typical fix: Replace the blown fuse or faulty relay. If the fuse blows again, the pump motor is shorted and must be replaced.
   Est. part cost: $5-$30

Rare But Worth Checking

• ECM Glitch in Freezing Temperatures: On some 2005-2006 models with the 4.7L engine, a known ECM glitch can falsely trigger P2445. This typically happens when starting in near-freezing temperatures and then accelerating past 50 mph, which then puts the vehicle into limp mode. Toyota had a limited service campaign for an ECM re-flash, but it is no longer available. A workaround is to let the vehicle warm up, shut it off, and restart it before driving.

Diagnosis Steps

1. Read the codes with an OBD-II scanner and confirm P2445 is present. Note any other codes, especially P0418 or any P244x valve codes.
2. On a cold start, listen for a vacuum cleaner-like sound from the engine bay for the first 30-60 seconds. No sound points to a dead pump or electrical issue.
3. Check the dedicated 50A fuse and relay for the air injection pump in the engine bay fuse box.
4. If electrics are good, use a bi-directional scanner to activate the air pump. Listen for it to run.
5. If the pump does not run when commanded, check for B+ voltage at the pump connector. If voltage is present, the pump motor has failed.
6. If the pump runs, the issue may be with the air switching valves or a blockage. Use the scanner to actuate the valves and monitor system pressure.
7. Visually inspect the air pump inlet and hoses for a disintegrated foam filter or other debris, as noted in TSB T-SB-0230-12. This is the primary failure mode.
8. If the code only appears in freezing weather after reaching ~50mph, suspect the ECM glitch on 2005-2006 models.

Parts You'll Likely Need

• Secondary Air Injection Pump (OEM #17600-0F010) — This is the most common failure point for code P2445, typically due to moisture or debris from its own filter causing the motor to seize.
  Trusted brands: Toyota (OEM), Dorman (P/N: 306-010)
  OEM price range: $800-$1200
  Aftermarket price range: $300-$600
• Air Switching Valve Assembly (OEM #25710-50022) — These valves are often contaminated by the same debris that destroys the pump and are replaced as a set during the repair.
  Trusted brands: Toyota (OEM), Dorman
  OEM price range: $350-$500
  Aftermarket price range: $150-$250
• SAI System Bypass Kit — Due to the extremely high repair cost, many owners opt for an aftermarket electronic bypass kit. These kits trick the ECU into thinking the system is working correctly, clearing the codes and limp mode. This is a permanent solution that prevents future failures of the mechanical parts. Note: This solution is for off-road use only and will not pass visual emissions inspection in some states.
  Trusted brands: Hewitt-Tech (Gen 1 or Gen 2 kits), Slyfox75 (available via forums)
  Aftermarket price range: $65-$450
• Intake Manifold Gasket (OEM #17171-50030) — Required for re-installing the intake manifold after accessing the pump and valves underneath.
  Trusted brands: Toyota (OEM), Fel-Pro (P/N: MS 96672)
  OEM price range: $40-$60
  Aftermarket price range: $20-$30

Related Codes That Often Appear With This One

• P0418 — This code indicates a circuit malfunction for the SAI pump relay. It often appears with P2445 when the pump motor has failed electrically or blown its fuse.
• P2440, P2441, P2442, P2443 — These codes indicate that the air switching valves are stuck open or closed. It's common for the entire system (pump and valves) to be compromised by debris or moisture.
• C1201 — This is an engine control system malfunction code that is often triggered when the vehicle enters 'limp mode', disabling VSC and TRAC systems as a result of the primary engine fault.

Technical Service Bulletins (TSBs) & Recalls

• T-SB-0230-12 Rev1: 'Air Injection System MIL "ON"' - Updated bulletin from Oct 2013 that explicitly adds P2445. It notes that debris from the air pump can contaminate other components and lists affected vehicles including the 4Runner, Land Cruiser, Sequoia, and Tundra with the 2UZ-FE engine.
• T-SB-0230-12: Original version of the above TSB from Nov 2012, with the same core information about debris causing system failure.

Platform-Specific Known Issues

• A major issue for this platform is that Toyota created a warranty extension (Customer Support Program ZT8) for this exact problem on the Tundra and Sequoia (which share the 2UZ-FE engine) but excluded the 4Runner and Lexus GX470, leaving owners to face a very expensive repair for a known design flaw.
• The location of the pump and valves under the intake manifold on the 4Runner and GX470 makes the repair significantly more labor-intensive and costly compared to the Tundra and Sequoia, where the pump is easily accessible in the engine bay.

Scan Tool Commands That Help

• Toyota Techstream: Active Test for Secondary Air Injection System — Used to manually command the SAI pump and air switching valves to operate. This allows a technician to verify the function of individual components without needing to wait for a cold start, which is the normal trigger for the system. It is a primary step in diagnosing if the pump motor has failed or if valves are not responding.

Wiring & Ground Locations

• A/PUMP Fuse 50A — In the main engine room fuse box (R/B), located on the left side of the engine compartment.. This is the main fuse for the secondary air injection pump. A seized or shorted pump motor will often blow this fuse. If the fuse is blown, the pump cannot run, directly causing a P2445 code. Checking this fuse is a primary and simple diagnostic step.
• Air Injection Control Driver — Located in the engine bay, outside the main fuse box, typically on the driver's side inner fender near the brake booster/master cylinder.. This is the electronic controller or relay module for the air pump, not a standard relay. It receives the command from the ECM and powers the high-current pump motor. A failure in this driver can prevent the pump from activating, leading to P2445.
• Engine Control Module (ECM) — Located behind the right side of the dashboard, often behind the glove box.. This is the source of the command to activate the SAI system. For the Hewitt-Tech Gen-II bypass kit on the 4.7L 4Runner, three wires must be passed through the firewall and connected to the ECM wiring, making its location critical for that specific repair.

Real Owner Repair Stories

• Reddit user Boston_Jon_189 and others in r/4Runner (2006 Toyota 4Runner V8) — Check engine light, VSC TRAC OFF, and Traction Off lights illuminated, with code P2445.
  ❌ Tried (didn't work) N/A, user went straight for the common solution.
  ✅ What actually fixed it The consensus and direct advice was to install an inexpensive aftermarket bypass kit to permanently fix the issue. One user confirmed, 'Get the bypass kit. That's what I did and it's never come back.'
• Toyota-4Runner.org user NELyons (2005 Toyota 4Runner 4.7L V8) — P2445 code.
  ❌ Tried (didn't work) Replaced check valves, Replaced control valve, Replaced air pump, Replaced control driver, Replaced all vacuum hoses
  ✅ What actually fixed it After replacing nearly every component in the system without success, the user was advised by another forum member that a bypass kit is the common, ultimate solution for this 'rampant problem'. The original poster 'liked' this response, indicating it was the correct path forward.
• Reddit user _I_Hate_Cats (2008 Toyota 4Runner V8) — P2445 code.
  ✅ What actually fixed it Installed a Slyfox-brand bypass kit with block-off plates. The user provided a specific installation tip: instead of wrapping wires around the relay spades as some videos show, they recommended inserting the bypass wires directly into the fuse box slots where the relay plugs in, then reinstalling the relay over them for a more secure connection.

OEM Part Supersession History

• 25710-50020, 25710-50021 → 25710-50022 — Standard part revision and improvement by the manufacturer.
  Heads up: The newer part number (25710-50022) is the correct and current replacement for the older versions. Using the older part numbers is not recommended if the new one is available.

Model Year Variations Within This Range

• 2005-2006: These model years are known to have an ECM software glitch that can falsely trigger code P2445 and limp mode. The failure is induced by a specific sequence: starting in freezing temperatures and then accelerating past 50 mph. This is a software issue, not a hardware failure.