P0204 Cylinder 4 fuel injector circuit fault

Cylinder 4 injector circuit malfunction

P0204 in short

P0204 means the computer found a fault in the electrical circuit of the cylinder 4 fuel injector. Causes include a failed injector, a damaged connector or harness, or a computer driver fault. Expect misfire, rough running or reduced power, so get it checked soon rather than driving far.

Each fuel injector is switched by the engine computer. P0204 is set when the computer sees a problem in the circuit for cylinder 4, such as an open, a short or a missing signal, rather than simply a lean or rich mixture.

GM, Ford and Mazda bulletins describe the usual result: rough running, a misfire, reduced power and a lit light. A GM 2021 to 2022 truck bulletin replaces the injector and its wiring harness.

Cylinder numbering follows the maker, so check which physical cylinder is number 4 in your service information.

Most likely causes

  1. Failed fuel injector on cylinder 4

    Common general cause
    Why it ranks here
    An open or shorted injector coil is the most direct way to set an injector circuit code, and GM and Ford bulletins replace injectors for this family of codes.
    What would change this
    Rises if the injector coil resistance is out of spec or it does not click. Falls if it tests normally.
    How to test the fuel injector

  2. Damaged injector connector or wiring harness

    Supported by vehicle data
    Why it ranks here
    GM bulletin 22-NA-087 and the Ford and Volkswagen bulletins replace or repair the harness along with the injector.
    What would change this
    Rises if the connector is loose, burnt or the harness is chafed. Falls if wiring tests clean.

  3. Engine control module injector driver fault

    Possible — needs testing
    Why it ranks here
    A computer driver failure is possible after the injector and wiring are ruled out.
    What would change this
    Rises if injector and wiring test good and the code stays on cylinder 4. Falls otherwise.
    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 codes. Note other injector codes and misfire codes such as P0304 stored with P0204.

    Low riskTool: OBD-II scan tool

  2. Have the injector connector checked, its coil resistance measured and a noid light or scan-tool injector test run on cylinder 4.

    Best left to a shopTool: multimeter, noid light

    Warning:Fuel injectors run under fuel pressure and near hot parts. Let a shop do it.

Symptoms

  • Check engine light with a rough idle or misfire
  • Hesitation or low power
  • Flashing check engine light Gets more serious: stop and have it checked.

Compare with: Rough idle with the check engine light on, Car shaking with the check engine light on

How to fix

  1. With the engine off and cool, check that the injector connector for the cylinder is fully seated.

  2. Ask a dealer whether your VIN has an injector or harness bulletin.

Parts and cost context

  • Fuel injector:Confirm with injector tests 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

Chevrolet

  • 2004–2005 · Silverado 1500

    Supported by vehicle data

    GM bulletin 060604026 covers 2004 to 2005 trucks with an injector driver circuit concern. Not verified as current.

  • 2021–2022 · Silverado 1500

    Supported by vehicle data

    GM bulletin 22-NA-087 replaces the injector and wiring harness for injector circuit codes on 2021 to 2022 trucks. Not verified as current.

  • 060604026Status unverified

    Intermittent light, reduced power, fuel injector driver circuit codes

    2004–2005silverado-1500 · issued · NHTSA 10020835

    Covers an intermittent check engine light with reduced engine power and fuel injector driver circuit codes P0201 to P0208 on 2004 to 2005 trucks. The summary mentions cylinder bank shutdown codes.

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

  • 22-NA-087Status unverified

    Replace fuel injector and wiring harness for P0201 to P0206 and P0216

    2021–2022silverado-1500, tahoe, suburban · issued · NHTSA 10211935

    GM procedure to replace the fuel injector and its wiring harness for a lit light with injector circuit codes P0201 to P0206 and P0216 on 2021 to 2022 trucks.

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

Ford

  • 2008 · F-250 Super Duty

    Supported by vehicle data

    Ford bulletin 19620 covers 2008 Super Duty with injector circuit open codes and a misfire. Not verified as current.

  • 2005–2006 · Focus

    Supported by vehicle data

    Ford bulletin 19056 covers rough running with injector codes on the 2005 to 2006 Focus. Not verified as current.

  • 19620Status unverified

    Injector circuit open codes P0201 to P0208 with misfire or lack of power

    2008f-250, f-350 · issued · NHTSA 10021620

    Covers injector circuit open codes with a misfire, rough running or lack of power on 2008 Super Duty trucks.

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

  • 19056Status unverified

    MIL on and rough running with P0201 to P0204

    2005–2006focus · issued · NHTSA 10019083

    Covers a check engine light and rough running with multiple injector codes in the powertrain computer.

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

Mazda

  • 2013–2016 · Mazda3

    Supported by vehicle data

    Mazda bulletin 01-017-16-3242 covers rough running with P0201 and P0204. Not verified as current.

  • 01-017-16-3242Status unverified

    Rough running with P0201 and P0204 or P0202 and P0203

    2013–2016mazda3, cx-5, mazda6, cx-7 · issued · NHTSA 10092582

    Covers an engine that runs rough with the light on and codes P0201 and P0204 or P0202 and P0203, which are injector circuit pairs.

    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 injector circuit code for cylinder 1; GM and Ford bulletins list the whole P0201 to P0208 family together.

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

    Same system Supported by vehicle data

    P0203 is the cylinder 3 injector circuit code; Mazda pairs P0201 with P0204 and P0202 with P0203.

  • P0207Cylinder 7 fuel injector circuit fault

    Same system Supported by vehicle data

    P0207 is the cylinder 7 injector circuit code in the same family.

  • P0300Random or multiple-cylinder misfire detected

    Shares causes Common general cause

    A dead injector can cause random misfire, so P0300 may be stored with P0204.

All Fuel pump and injectors codes

P0204 questions

Is P0204 the same as a misfire code?

No. P0204 is an electrical fault in the injector circuit, but it can cause a misfire, so P0304 may appear with it.

Sources and review

  1. Chevrolet 060604026: Intermittent light, reduced power, fuel injector driver circuit codes — NHTSA manufacturer communications ,
  2. Ford 19620: Injector circuit open codes P0201 to P0208 with misfire or lack of power — NHTSA manufacturer communications ,
  3. P0204 trouble code explanation — TroubleCodes.net
  4. P0204 OBD-II trouble code — PartsAvatar
  5. Chevrolet 22-NA-087: Replace fuel injector and wiring harness for P0201 to P0206 and P0216 — NHTSA manufacturer communications ,
  6. Mazda 01-017-16-3242: Rough running with P0201 and P0204 or P0202 and P0203 — NHTSA manufacturer communications ,
  7. Ford 19056: MIL on and rough running with P0201 to P0204 — NHTSA manufacturer communications ,
Last reviewed
Written by
Saurabh K.
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