P0035 Turbo or supercharger bypass valve control circuit reads high

Turbocharger bypass valve circuit high / boost bypass solenoid

P0035 in short

P0035 means the computer sees a high or shorted signal in the circuit that controls the turbo or supercharger bypass valve. On Honda turbo engines a broken wire at the solenoid connector is a documented cause. A faulty valve is the other common one. Have it inspected soon, because power can drop without warning.

A turbo or supercharger bypass valve opens to release extra boost pressure, for example when you lift off the throttle. The engine computer drives the valve through a small solenoid and watches the circuit. If the circuit voltage is higher than it should be, or the line looks open or shorted, it sets P0035.

The code is about the electrical circuit, not about boost itself, so the first suspects are the wiring and connector at the solenoid, then the valve and solenoid. Honda has two bulletins on its 2017 Civic where a wire in the solenoid's 2-pin connector breaks from heat and vibration, which opens the circuit and sets P0035 together with a Rev Match System Problem or Emissions System Problem message.

Kelley Blue Book says the car may go into a limp mode with reduced speed. One Ford Escape owner reported P0035 on two replacement turbochargers, with a dealer finding a valve stuck on each. Treat repeated returns of the code as a sign the valve or its control needs a closer look, not just a reset.

Most likely causes

  1. Broken wire or poor connection at the bypass solenoid connector

    Supported by vehicle data
    Why it ranks here
    Honda bulletins A18-044 and ATS171102 name a broken wire in the turbocharger bypass solenoid 2-pin connector as the likely cause on the 2017 Civic. They are unverified flat-file summaries, so this is vehicle data, not confirmed.
    What would change this
    Rises if the connector wires are damaged, loose or corroded or the harness is chafed. Falls if the wiring tests good from solenoid to computer.

  2. Bypass valve or solenoid failed inside

    Common general cause
    Why it ranks here
    Kelley Blue Book lists an internal fault in the bypass valve as the first cause. A Ford Escape owner reports a valve stuck closed on one turbo and open on another.
    What would change this
    Rises if the circuit tests good and the valve does not click or move when commanded. Falls if the valve works and the wiring is damaged.

  3. Engine computer driver fault (rare)

    Possible — needs testing
    Why it ranks here
    Kelley Blue Book lists the engine computer last and calls it rare, so it is only suspected after wiring and valve both test good.
    What would change this
    Rises if the solenoid wiring and valve are both good and the fault stays. Falls if either is faulty.
    How to test the engine control module (ecm / pcm)

What to test first

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

  1. Read all stored codes and freeze-frame data and note any messages in the dashboard such as Rev Match System Problem or Emission System Problem.

    Low riskTool: OBD-II scan tool

    • IfOther turbo or boost codes are stored with P0035

      It meansBoost control may be affected beyond the circuit; mention all codes to the shop.

      Go to step 2

    • IfP0035 is the only code

      It meansGo on to inspect the solenoid wiring.

      Go to step 2

  2. With the engine off and cool, look at the bypass solenoid connector and the wires going into it for broken or loose wires, corrosion or chafing.

    Use caution

    Warning:The turbocharger and exhaust parts run extremely hot and stay hot after the engine stops. Let the engine cool fully before reaching near them.

  3. Have the solenoid resistance and the power, ground and signal wires tested with a multimeter or bidirectional scan tool that can command the valve.

    Best left to a shopTool: multimeter, bidirectional scan tool

    Warning:Back-probing live circuits can damage the computer; leave this to a technician.

Symptoms

  • Check engine light on
  • Rev Match System Problem or Emission System Problem message on some Hondas
  • Reduced power or limp mode, sometimes with other warning lights Gets more serious: stop and have it checked.
  • Poorer fuel economy

Compare with: Check engine light with loss of power

How to fix

  1. With the engine off and cool, look at the bypass solenoid connector for wires that look broken, loose or corroded.

  2. Ask a dealer whether a bulletin applies to your VIN.

Parts and cost context

  • Engine control module (ECM / PCM):The computer is rarely at fault; test the wiring and valve first. Labor 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

Honda

  • 2017–2018 · Civic

    Supported by vehicle data

    Honda bulletins A18-044 and ATS171102 tie P0035 on the 2017 Civic (including the Type R) to a broken wire in the bypass solenoid connector. A 2018 owner also reports P0035 with sudden loss of power. Whether the bulletins are still current is not verified.

  • A18-044Status unverified

    MIL on with P0035 and Rev Match / Emissions System Problem

    2017civic, civic-type-r · NHTSA 10142655

    Due to heat and vibration the solenoid connector wire breaks and opens the circuit to the turbocharger bypass control solenoid. The NHTSA summary does not give the repair.

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

  • ATS171102Status unverified

    P0035 with Rev Match or Emission System Problem (tech line summary)

    2017civic · NHTSA 10123193

    Points to a broken wire in the 2-pin turbocharger bypass solenoid connector as the likely cause.

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

Ford

  • 2018 · Escape

    Supported by vehicle data

    One 2018 Escape owner reports P0035 on two replacement turbochargers, with dealers finding a valve stuck on each. A single complaint, not a verified pattern.

No curated relationships for P0035 yet.

All Turbocharging, fuel pressure and EGR codes

P0035 questions

Can I drive with P0035?

Not for long. Kelley Blue Book calls the code serious and says limp mode can follow, and one Civic owner lost power suddenly. Get it checked soon and stop if power drops or other warning lights come on.

Is P0035 a crankshaft sensor code?

No. It is the turbo or supercharger bypass valve circuit, and Honda's own bulletins describe it that way.

Sources and review

  1. P0035 turbo or supercharger bypass valve circuit high — Kelley Blue Book
  2. NHTSA complaint ODI 11616513, 2018 Honda Civic: P0035 described as turbo bypass solenoid high voltage or circuit; car lost power with many warning lights — NHTSA
  3. Honda bulletin A18-044: P0035 (turbocharger bypass control solenoid valve circuit high) with Rev Match / Emissions System Problem messages; coupler wire oscillates and opens the circuit — Honda
  4. Honda bulletin ATS171102: P0035 with Rev Match or Emission System Problem; broken wire in the 2-pin solenoid connector likely — Honda
  5. NHTSA complaint ODI 11496765, 2018 Ford Escape: both replacement turbochargers showed P0035; dealer said a valve was stuck closed on one and open on the other — NHTSA
Last reviewed
Written by
Saurabh K.
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