P2433 Secondary air system pressure or flow sensor circuit reading too high (bank 1)

Secondary air injection air flow/pressure sensor circuit high

P2433 in short

P2433 means the secondary air injection pressure or flow sensor circuit on bank 1 is reading higher than expected. Causes include the sensor or its wiring, a failing air pump, or stuck valves. Some Toyota trucks have gone into limp mode with it, so have it inspected soon rather than ignoring the light.

The secondary air system blows fresh air into the exhaust after a cold start, with a sensor that confirms the air is flowing. P2433 sets when that sensor circuit reads high.

Volkswagen groups P2431, P2432 and P2433 in one bulletin on 2005-2012 models, and a 2010 Jetta owner reports an out-of-range pressure sensor circuit. On 2012 Tacoma and Tundra trucks owners report the code with limp mode, and one Tundra with failed air injection pumps.

KBB lists the same causes for the high-circuit code as for its siblings: the pump, check valve, solenoid, sensor, wiring and rarely the computer.

Most likely causes

  1. Pressure sensor or its wiring reading high

    Supported by vehicle data
    Why it ranks here
    A 2010 Jetta owner reports the secondary air pressure sensor circuit out of range (P2431/P2433), and VW bulletin 261403 lists the code. KBB lists the sensor and wiring.
    What would change this
    Rises if the sensor reading is stuck high when the pump is off. Falls if it follows the pump normally.

  2. Air injection pump failure

    Supported by vehicle data
    Why it ranks here
    A 2012 Tundra owner reports failed air injection pumps with P2433 and limp mode, and KBB lists the pump.
    What would change this
    Rises if the pump does not run or is noisy. Falls if it runs and flows.
    How to test the secondary air pump

  3. Check valve or air control solenoid

    Common general cause
    Why it ranks here
    KBB lists the one-way check valve and the air control solenoid among the causes of this code.
    What would change this
    Rises if air does not reach the exhaust. Falls if both valves work.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all codes. Note whether P2431, P2432, P0412 or P0411 are stored with P2433.

    Low riskTool: OBD-II scan tool

    • IfP2431 or P2432 stored too

      It meansThey share one sensor circuit; test it first.

      Go to step 2

    • IfP2433 alone

      It meansInspect the circuit.

      Go to step 2

  2. Inspect the secondary air pressure sensor connector, wiring and hoses for corrosion, damage or loose fittings.

    Low risk

  3. Run the secondary air pump with a bidirectional scan tool and watch the sensor reading.

    Best left to a shopTool: bidirectional scan tool

    Warning:The pump and exhaust parts can be hot. Leave this to a shop.

Symptoms

  • Check engine light
  • Limp mode and traction control light (Toyota trucks) Gets more serious: stop and have it checked.
  • Rough idle after a cold start Gets more serious: stop and have it checked.

Compare with: Rough idle with the check engine light on

How to fix

  1. Ask a dealer whether your VIN has an open secondary air bulletin or an updated sensor or hose for P2433.

Parts and cost context

  • Secondary air pump:Pumps are costly; confirm the fault before replacing. Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Volkswagen

  • 2005–2012 · Jetta

    Supported by vehicle data

    Volkswagen bulletin 261403 lists P2433 with P2431 and P2432; one 2010 Jetta owner reports a pressure sensor circuit out of range.

  • 261403Status unverified

    MIL on, secondary air DTCs P2431, P2432, P2433 stored

    2005–2012jetta, beetle, golf, passat · NHTSA 10239827

    Secondary air codes stored in the ECM fault memory.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Toyota

  • P2431Secondary air system pressure or flow sensor reading out of range (bank 1)

    Same system Supported by vehicle data

    P2431 is the range/performance code for the same sensor circuit.

  • P2432Secondary air pressure sensor signal too low (bank 1)

    Same system Supported by vehicle data

    P2432 is the low-circuit code for the same sensor circuit. Volkswagen bulletin 261403 lists P2431, P2432 and P2433 together.

  • P0411Secondary air injection flow not as expected

    Same system Possible — needs testing

    P0411 is the secondary air injection system incorrect flow code, which can appear when the pump or its valves are failing.

All Secondary air injection codes

P2433 questions

What is the difference between P2431 and P2433?

P2431 is range or performance and P2433 is a high circuit reading on the same secondary air sensor. The checks are the same.

Sources and review

  1. P2433 code: secondary air injection system air flow/pressure sensor circuit high bank 1 — Kelley Blue Book (KBB Service Advisor)
  2. NHTSA complaint ODI 1500006: 2012 Toyota Tundra, P2433 — NHTSA Office of Defects Investigation (owner complaint)
  3. NHTSA complaint ODI 876748: 2010 Volkswagen Jetta, P2431 and P2433 — NHTSA Office of Defects Investigation (owner complaint)
  4. MIL on, secondary air DTCs P2431, P2432, P2433 stored in ECM fault memory (Volkswagen bulletin 261403) — Volkswagen of America / NHTSA
  5. NHTSA complaint ODI 1376864: 2012 Toyota Tacoma, P0412 P2433 P2438 P2442 — NHTSA Office of Defects Investigation (owner complaint)
Last reviewed
Written by
Saurabh K.
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