P0202 Fuel injector circuit fault on cylinder 2

Injector circuit malfunction, cylinder 2

P0202 in short

P0202 means the computer found an electrical fault in the fuel injector circuit for cylinder 2. A failed injector, damaged wiring or a loose connector is the usual cause. The engine may run rough, lose power or stall, so have it inspected soon and do not ignore a flashing check engine light.

The computer fires each injector with a short electrical pulse and watches the circuit for the expected response. If it does not see the change it expects on the cylinder 2 circuit, it sets P0202. The code points at the electrical circuit, not at fuel pressure.

The cause is most often the injector coil itself, the wiring or connector for that injector, or, less often, the driver inside the computer. Several makers have bulletins about it: GM names a damaged engine wiring harness and injector on some trucks, and Mazda and Ford list it with rough running and misfire codes.

The code often appears with the codes for other cylinders (P0201, P0203, P0204). When several injector circuits fail at once, look at what they share, such as power supply, a common connector or the wiring harness, before replacing injectors.

Most likely causes

  1. Failed cylinder 2 fuel injector

    Supported by vehicle data
    Why it ranks here
    The code names the cylinder 2 injector circuit. A 2021 Porsche shop invoice and an Acura dealer diagnosis in complaints both end in an injector replacement, and GM bulletins prescribe replacing the affected injector.
    What would change this
    Raises if the injector resistance is out of range or swapping it with another cylinder moves the code to that cylinder; lowers if the injector tests good.
    How to test the fuel injector

  2. Damaged wiring or connector at the injector

    Supported by vehicle data
    Why it ranks here
    GM bulletins for 2020 to 2024 trucks and SUVs have the dealer inspect or replace the engine wiring harness, and Mazda and Ford list the code with misfire and rough running.
    What would change this
    Raises if wiggling the connector or harness changes the engine running or sets other injector codes; lowers if the harness checks good end to end.
    How to test the fuel injector

  3. Injector connector or its support (known on some GM trucks)

    Supported by vehicle data
    Why it ranks here
    For 2004 GM Kodiak trucks, GM published a revised 90 degree injector connector and harness bracket kit for this code with reduced power.
    What would change this
    Only applies to the listed GM truck; raises if the connector shows heat damage or movement.
    How to test the fuel injector

  4. Injector driver in the engine computer

    Possible — needs testing
    Why it ranks here
    Listed by a reference as a less common cause. One complaint reports that GM recommended a replacement computer for several injector codes, but the result is not documented.
    What would change this
    Consider only after the injector, the wiring and the power supply to the injectors all test good.
    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 the freeze-frame data with a scan tool, and note whether other injector codes (P0201, P0203, P0204) or misfire codes are stored with P0202.

    Low riskTool: OBD-II scan tool

    • IfOnly P0202 is stored, with a misfire on cylinder 2

      It meansThe fault is probably local to the cylinder 2 injector or its connector.

      Go to step 2

    • IfSeveral injector circuit codes are stored together

      It meansLook for something they share, such as the injector power supply or a common harness section.

      Go to step 2

  2. With the engine off and cool, look at the cylinder 2 injector connector and the visible harness for chafing, heat damage, a loose or corroded plug.

    Low risk

  3. Measure the injector coil resistance and the injector circuit voltage and driver signal against the vehicle service information; swap the cylinder 2 injector with another cylinder and see whether the code moves.

    Best left to a shopTool: multimeter, noid light or scope

    Warning:The fuel rail is under pressure and fuel is flammable; releasing pressure and handling injectors is a job for a shop. Probing a live injector connector can also short the circuit and damage the computer driver.

Symptoms

  • Check engine light with rough running or a misfire
  • Loss of power or engine shaking, especially under load
  • Check engine light flashing, or the engine stalls or will not start Gets more serious: stop and have it checked.

Compare with: Car shaking with the check engine light on

How to fix

  1. With the engine off and cool, look at the injector connectors and visible wiring for damage or a loose plug.

  2. Ask a dealer whether your VIN has an open bulletin or warranty coverage for injector or harness faults.

Parts and cost context

  • Fuel injector:Replace an injector only after the circuit tests point at it. On some GM models the wiring harness is replaced together with the injector. 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

Mazda

  • 2014–2016 · Mazda3

    Supported by vehicle data

    Mazda bulletin 01-017-16-3242 lists P0202 with rough running and misfire codes on the Mazda3. The bulletin is on NHTSA; whether it is still current is not verified.

  • 2016–2017 · Mazda2

    Supported by vehicle data

    Mazda bulletin 01-004-17-3317A lists P0202 with rough running on the Mazda2. Status not verified.

  • 01-017-16-3242Status unverified

    Rough running with P0201/P0204 or P0202/P0203

    2014–2016mazda3 · issued · NHTSA 10092582

    Lists P0202 as the cylinder 2 injector circuit open fault and notes misfire codes are usually stored too. The repair is not in the NHTSA summary.

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

  • 01-004-17-3317AStatus unverified

    Rough running with P0201/P0204 or P0202/P0203

    2016–2017mazda2 · issued · NHTSA 10120370

    Same wording as the Mazda3 bulletin, applied to the Mazda2.

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

Ford

  • 2021 · Expedition

    Supported by vehicle data

    Ford SSM 49759 covers no-start and misfire with P0202 among P0201 to P0206 on the 2021 Expedition. Status not verified.

  • SSM 49759Status unverified

    No-start, rough running or misfire with P0201 to P0206

    2021expedition · issued · NHTSA 10191523

    Tells the technician to follow the Pinpoint Tests in the Powertrain Control/Emissions Diagnosis Manual.

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

Chevrolet

  • 2021–2022 · Suburban

    Supported by vehicle data

    GM 22-NA-087 replaces the injector and wiring harness for these codes on the 2021 Suburban. Status not verified.

  • 22-NA-087Status unverified

    Replace injector and wiring harness for P0201 to P0206 and P0216

    2021–2022suburban · issued · NHTSA 10211935

    Prescribes replacing the fuel injector and the engine wiring harness.

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

GMC

  • 2020 · Sierra 1500

    Supported by vehicle data

    GM PIT5751 has the dealer inspect the engine wiring harness for damage when these injector codes set on the 2020 Sierra 1500. Status not verified.

  • 2024 · Yukon XL

    Supported by vehicle data

    GM PIE0802A closes an engineering inquiry on P0202 with a wire harness and injector replacement on the 2024 Yukon XL. Status not verified.

  • PIT5751Status unverified

    Inspect engine wiring harness for damage with injector codes

    2020sierra-1500 · issued · NHTSA 10178321

    Tells the dealer to inspect the engine wiring harness for damage when these injector codes set.

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

  • PIE0802AStatus unverified

    Check engine lamp with P0202, replace wire harness and injector

    2024yukon-xl · issued · NHTSA 11011984

    Engineering closure: replace the wire harness and the affected injector.

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

  • P0201The engine computer has detected an electrical fault in the cylinder 1 fuel injector circuit

    Same system Supported by vehicle data

    P0201 is the same fault on cylinder 1. Mazda and Ford bulletins list P0201 to P0204 together, which points to something shared.

  • P0203The engine computer has detected an electrical fault in the cylinder 3 fuel injector circuit

    Same system Supported by vehicle data

    P0203 is the same fault on cylinder 3; Mazda lists P0202 with P0203 in one bulletin.

  • P0300Random or multiple-cylinder misfire detected

    Primary / secondary Supported by vehicle data

    Likely primary: P0202. A dead injector causes a misfire; Mazda notes that misfire codes are usually stored at the same time.

All Fuel pump and injectors codes

P0202 questions

Does P0202 mean the injector is bad?

Not always. The code is about the electrical circuit. A damaged wire or connector is as likely as a failed injector on some models, so test the circuit before buying an injector.

Can I keep driving with P0202?

Short trips are possible if the engine runs normally, but the cylinder may misfire and some owners report stalling or sudden power loss. Get it checked soon, and stop if the light flashes.

Sources and review

  1. GM 05-06-04-047: SES light and reduced power with P0202 and P2146 or P0207 and P2149 (2004 Chevrolet Kodiak) — General Motors / NHTSA ,
  2. Ford SSM 49759: no-start, rough running or misfire with P0201 to P0206 (2021 Expedition and Navigator) — Ford Motor Company / NHTSA ,
  3. NHTSA complaint ODI 2182138: 2021 Porsche 911, P0202 and P0204 — NHTSA (owner complaint)
  4. NHTSA complaint ODI 1713800: 2013 Acura ILX, P0202 with flashing lights and no power — NHTSA (owner complaint)
  5. GM PIE0802A: Yukon XL, check engine lamp with P0202, replace wire harness and affected injector — General Motors / NHTSA ,
  6. GM PIT5751: SES MIL with P0201 to P0206 and P0216, inspect engine wiring harness for damage (2020 Sierra 1500) — General Motors / NHTSA ,
  7. GM 22-NA-087: replace fuel injector and wiring harness for MIL with P0201 to P0206 and/or P0216 (2021 Suburban 1500) — General Motors / NHTSA ,
  8. P0202 Trouble Code Explanation — TroubleCodes.net
  9. Mazda 01-017-16-3242: rough running with P0201/P0204 or P0202/P0203 (2015 Mazda3) — Mazda North American Operations / NHTSA ,
  10. Ford 19056: MIL and rough running with P0201 to P0204 in the PCM (2006 Focus) — Ford Motor Company / NHTSA ,
  11. Mazda 01-004-17-3317a: rough running with P0201/P0204 or P0202/P0203 (2017 Mazda2) — Mazda North American Operations / NHTSA ,
Last reviewed
Written by
Saurabh K.
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