P0201 The engine computer has detected an electrical fault in the cylinder 1 fuel injector circuit

Injector circuit malfunction, cylinder 1

P0201 in short

P0201 means the computer found an electrical problem in the cylinder 1 fuel injector circuit. A failed injector, wiring or connector fault, or a computer injector driver are the usual causes. Expect misfires, stalling or hard starting. Get it checked soon, and stop driving if the light flashes.

The computer switches each injector on and off and looks for the matching change in current. P0201 sets when cylinder 1's injector does not respond as expected.

The injector itself, the wiring and connector, or the injector driver inside the computer can be at fault. TroubleCodes.net says misfire codes often come with it.

Some makers have specific findings: a Dodge bulletin for the 2007 Ram 2500 diesel says to check the wiring loom and connector in the valve cover gasket before replacing injectors, and GM and Ford have bulletins for several injector circuit codes on their diesels and trucks.

Most likely causes

  1. Failed fuel injector on cylinder 1

    Common general cause
    Why it ranks here
    TroubleCodes.net lists a failed injector first for P0201 and gives resistance and balance tests to confirm.
    What would change this
    Rises if injector resistance is out of specification or it does not click or pulse. Falls if the injector tests good and the wiring is faulty.
    How to test the fuel injector

  2. Wiring or connector fault in the injector circuit

    Supported by vehicle data
    Why it ranks here
    TroubleCodes.net lists wiring and connector faults, and a Dodge bulletin for the 2007 Ram 2500 diesel says to check the wiring loom and connector in the valve cover gasket before replacing injectors.
    What would change this
    Rises if the harness or connector is damaged, or continuity fails. Falls if the circuit tests good end to end.

  3. Injector driver in the engine computer

    Possible — needs testing
    Why it ranks here
    TroubleCodes.net lists a computer injector driver fault. It ranks last because the injector and wiring are checked first.
    What would change this
    Rises if the injector and wiring are good and the noid light does not flash. Falls if the injector or wiring 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. Note any misfire codes (such as P0301) or other injector circuit codes.

    Low risk

    • IfSeveral injector circuit codes are stored together

      It meansA shared wiring, connector or computer fault is more likely than several bad injectors.

      Go to step 2

    • IfOnly P0201 is stored

      It meansCheck the cylinder 1 injector and wiring.

      Go to step 2

  2. With the engine off, look over the cylinder 1 injector, connector and harness for damage and corrosion.

    Low risk

  3. Have a shop check the injector control signal with a noid light or scope, test power and continuity, and measure injector resistance against the maker specification.

    Best left to a shopTool: noid light, multimeter, oscilloscope

    Warning:Fuel is under pressure and injector circuits can carry high voltage on some engines. Let a shop do these tests.

Symptoms

  • Check engine light
  • Rough running or a misfire on one cylinder
  • Hard starting, cranking without starting, or stalling Gets more serious: stop and have it checked.
  • Flashing check engine light 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 over the cylinder 1 injector connector and harness for damage or corrosion.

Parts and cost context

  • Fuel injector:Check wiring and connectors before replacing an injector. 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

Ford

  • 2008 · F-250 Super Duty

    Supported by vehicle data

    Ford TSB 19813 covers an open injector circuit with P0201 to P0208, misfire and lack of power on 2008 Super Duty trucks. Whether it is still current is not verified.

  • 2005–2006 · Focus

    Supported by vehicle data

    Ford TSB 19056 covers rough running with P0201 to P0204. Whether it is still current is not verified.

  • 19813Status unverified

    Injector circuit open, P0201-P0208 with misfire, rough running or lack of power

    2008f-250-super-duty · NHTSA 10022657

    Service information for an open injector circuit. The summary also names the F-350 through F-750 Super Duty and does not give the repair.

    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-P0204

    2005–2006focus · NHTSA 10019083

    Service information for multiple injector circuit codes on the Focus. The summary does not give the repair.

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

  • 16-0163Status unverified

    Drivability issues with many DTCs including P0201-P0204

    2014–2016transit-connect · NHTSA 10094582

    Covers 2.5L Transit Connect vans that set many codes; follow the service procedure. The summary does not describe it.

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

Chevrolet

  • 2009–2015 · Traverse

    Supported by vehicle data

    GM PIP4924C lists P0201 to P0206 among codes with a misfire. Whether it is still current is not verified.

  • PIP4924CStatus unverified

    Service engine soon light and misfire, P0201-P0206 among codes

    2009–2015traverse · NHTSA 10112961

    Preliminary information for vehicles with a misfire and many injector and cylinder-specific codes. The summary also names Saturn Outlook, Buick Enclave and others and does not give the repair.

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

  • 01361Status unverified

    LB7 6.6L diesel with P0201 and P0208

    2001–2003silverado-2500-hd, silverado-3500-hd · NHTSA 10004142

    Service information for P0201 and P0208 on the LB7 Duramax 2500 HD and 3500. The summary does not give the repair. The summary also covers the GMC Sierra HD.

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

Saturn

  • 2009–2010 · Outlook

    Supported by vehicle data

    The same GM PIP4924C information names the Outlook. Whether it is still current is not verified.

  • PIP4924C-saturnStatus unverified

    Service engine soon light and misfire, P0201-P0206 among codes

    2009–2010outlook · NHTSA 10112961

    Same GM preliminary information as the Traverse entry; the summary does not give the repair.

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

Dodge

  • 2007 · Ram

    Supported by vehicle data

    A Dodge bulletin says to check the wiring loom and connector in the valve cover gasket before replacing injectors for P0201 to P0206. Whether it is still current is not verified.

  • 9002688Status unverified

    Check valve cover gasket wiring before replacing injectors (P0201-P0206)

    2007ram · NHTSA 10128971

    Before replacing injectors for P0201 to P0206, make sure the wiring loom or connector in the valve cover gasket is not the cause and the wiring nuts are torqued correctly.

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

  • P0301Misfire detected in cylinder 1

    Primary / secondary Common general cause

    Likely primary: P0201. A dead injector on cylinder 1 can cause the cylinder 1 misfire code P0301; fix the injector circuit first. TroubleCodes.net says misfire codes often come with it.

All Fuel pump and injectors codes

P0201 questions

Is it safe to drive with P0201?

Not for long. A dead injector can cause misfires, stalling or no-start. A flashing light means stop.

Sources and review

  1. P0201 trouble code summary — TroubleCodes.net
  2. Bulletin 9002688 Check the valve cover gasket wiring before replacing injectors — FCA US
  3. TSB 19813 Injector circuit open, P0201-P0208 with misfire, rough running or lack of power — Ford Motor Company
  4. PIP4924C Service engine soon light and misfire, P0201-P0206 among codes — General Motors
  5. TSB 19056 MIL on and rough running with P0201-P0204 — Ford Motor Company
Last reviewed
Written by
Saurabh K.
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