Secondary Air Injection Pump

This procedure covers the removal and replacement of the secondary air injection pump on the 2016-2021 Honda Civic 1.5L turbo engine, which supplies air to the exhaust system during cold starts to reduce emissions.

Warnings

Tools required

Parts

• Secondary air injection pump assembly × 1 — 17610-5AA-A01 (Use OEM specification)
• Air pump mounting gasket × 1 — Use OEM specification
• Air injection valve gasket × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cold to the touch
2. Disconnect negative battery terminal and wait 3 minutes for system discharge
3. Remove engine cover by pulling upward on all four corners to release clips
4. Raise vehicle on jack stands if additional underbody access is needed for heat shield removal
5. Take photos of electrical connector routing and hose connections before removal

Procedure

1. 1

   Remove heat shield and access covers
   Locate the secondary air injection pump on the driver's side of the engine bay near the firewall. Remove the heat shield bolts securing any protective covers around the pump and exhaust components. The heat shield may be in multiple pieces. Set aside bolts and shields in organized groups.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
2. 2

   Disconnect electrical connector
   Locate the electrical connector on the secondary air pump motor assembly. Press the locking tab and pull the connector straight away from the pump. Inspect connector terminals for corrosion or damage. If connector is tight, gently wiggle while pulling to avoid breaking tabs.
   ⚠Do not pull on wires. Always grasp the connector body to prevent wire damage.
3. 3

   Remove air inlet hose
   Loosen the hose clamp securing the fresh air inlet hose to the pump inlet. Use pliers to squeeze the clamp and slide it back along the hose. Twist the hose gently while pulling to remove it from the pump inlet fitting. Inspect the hose for cracks or deterioration.
   ℹ️The inlet hose typically draws air from near the fender well. Ensure the routing path is clear for reinstallation.
4. 4

   Disconnect outlet pipe connection
   Locate the outlet pipe that connects the pump to the exhaust manifold air injection valve. Remove the flange bolts securing this connection. The pipe may have a spring-loaded flange or fixed flange depending on production date. Separate the connection and remove the gasket.
   ⚠Exhaust flange gaskets are single-use. Do not reuse the old gasket even if it appears intact.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
5. 5

   Remove pump mounting bolts
   Identify the mounting bolts securing the secondary air pump assembly to its bracket on the engine block. There are typically 2-3 mounting bolts. Use a 12mm socket with extension to access the bolts. Support the pump with one hand while removing the final bolt to prevent it from falling.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
6. 6

   Remove secondary air pump assembly
   Carefully maneuver the pump assembly out of the engine bay. The pump may need to be tilted or rotated to clear surrounding components like the brake master cylinder and firewall. Work slowly to avoid damaging nearby wiring harnesses or brake lines. Remove the pump completely from the vehicle.
   ⚠The pump assembly weighs approximately 5-7 lbs. Maintain secure grip to prevent dropping onto painted surfaces or brake components.
7. 7

   Clean mounting surfaces
   Use a wire brush to clean the mounting bracket surfaces on the engine block where the pump was attached. Remove any old gasket material from the outlet pipe flange connection. Spray mounting bolt holes with brake cleaner and allow to dry. Inspect the mounting bracket for cracks or damage.
   ℹ️Do not allow debris to fall into open exhaust ports. Cover the air injection valve opening with a clean rag during cleaning.
8. 8

   Install new pump assembly
   Position the new secondary air pump assembly into the mounting location, routing it through the same path used during removal. Align the mounting holes with the bracket on the engine block. Hand-thread all mounting bolts before tightening any of them. This ensures proper alignment.
   ℹ️Verify the pump orientation matches the original installation. The inlet fitting should face toward the fender area.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
9. 9

   Connect outlet pipe to exhaust
   Install a new gasket onto the air injection valve flange on the exhaust manifold side. Position the outlet pipe from the pump onto the valve, ensuring the gasket is properly seated. Apply anti-seize to the flange bolt threads only (not the seating surfaces). Install and torque the flange bolts evenly in a cross pattern.
   ⚠Cross-tighten flange bolts gradually to prevent gasket distortion. Torque in 3 steps: 15 Nm, 30 Nm, then final 45 Nm.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
10. 10

    Reconnect inlet hose and electrical
    Slide the fresh air inlet hose onto the pump inlet fitting, ensuring it is fully seated. Position the hose clamp over the connection point and tighten securely. Connect the electrical connector to the pump motor, pressing firmly until the locking tab clicks into place. Tug gently to verify the connection is secure.
    ℹ️Ensure inlet hose routing does not contact hot exhaust components or moving engine parts.
11. 11

    Reinstall heat shields and covers
    Reinstall all heat shields and protective covers removed during disassembly. Ensure shields are properly positioned to protect surrounding components from exhaust heat. Install and torque all heat shield bolts and cover screws to specification.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

    Cover Screws10 Nm (8 lb-ft)

Reassembly

1. Reinstall engine cover by aligning clips and pressing down firmly at all four corners until seated
2. Reconnect negative battery terminal and tighten securely
3. Lower vehicle from jack stands if raised
4. Double-check all electrical connections and hose clamps are secure
5. Verify no tools or parts are left in the engine bay

Verification

• Start the engine and listen for unusual noises from the pump area during the first 60-90 seconds of cold start operation
• Check for exhaust leaks at the outlet pipe flange connection while engine is running
• Verify no check engine light remains illuminated after initial start cycle (MIL may flash briefly then clear)
• Allow engine to reach operating temperature and confirm no coolant or fluid leaks from disturbed components
• Perform a cold start test after the vehicle sits overnight to confirm pump activates properly (listen for pump motor operation during first 30-60 seconds)
• Scan for diagnostic trouble codes after 2-3 drive cycles to confirm system is functioning correctly

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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