OBD-II Generic Error Code P0273: How to Fix It

Medium 1–3 hours Medium Severity Verified July 2026
Error Code
P0273
Brand
OBD-II Generic
Product Type
automotive
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
1–3 hours
Error code P0273 indicates a low voltage or short circuit in the fuel injector circuit for cylinder 5. This can cause misfires, rough idling, and reduced engine performance. Follow this guide to diagnose and repair the issue safely.
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Tools You'll Need

How to Fix Error Code P0273

  1. Safety First & Gather Tools

    Always disconnect the battery before working on fuel injectors to prevent accidental fuel spray or electrical shorts.
  2. Scan and Verify the Code

  3. Locate Cylinder 5 Injector

  4. Visual Inspection of Wiring and Connector

  5. Test Injector Resistance

    Use proper probe connections to avoid shorting pins.
  6. Check Power and Ground at Injector Connector

    Do not ground the power wire; it can blow the fuse.
  7. Inspect Engine Control Module (ECM) Wiring

    Disconnect ECM before performing continuity tests to avoid damage.
  8. Replace Faulty Injector (If Needed)

    Release fuel pressure before removing injector. Consult service manual.

Parts You May Need

Fuel injector (cylinder 5)
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Injector O-rings and seals
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Wiring pigtail connector
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Fuel injector (cylinder 5)
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Injector O-rings and seals
Check Price on Amazon
Wiring pigtail connector
Check Price on Amazon
Fuel injector (cylinder 5)
Check Price on Amazon
Injector O-rings and seals
Check Price on Amazon
Wiring pigtail connector
Check Price on Amazon
Fuel injector (cylinder 5)
Check Price on Amazon
Injector O-rings and seals
Check Price on Amazon
Wiring pigtail connector
Check Price on Amazon
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When to Call a Professional

If the code persists after checking all wiring and replacing the injector, or if you are uncomfortable working with fuel systems or electrical diagnostics, consult a professional mechanic. Additionally, suspect a faulty ECM or internal engine issues (e.g., compression loss) that require advanced diagnosis.

Frequently Asked Questions

Can I drive with a P0273 code?
It's not recommended. The low injector circuit can cause misfires, poor fuel economy, and catalytic converter damage. You may notice rough idle and loss of power.
What causes P0273?
Common causes include a faulty fuel injector, wiring issues (open/short), a blown fuse, or a problem with the engine control module (ECM).
How much does it cost to fix P0273?
DIY cost is $50–150 for a new injector. Professional repair ranges from $200–500 depending on labor rates and the exact cause.
Will a bad injector cause a check engine light?
Yes, the ECM monitors injector circuit voltage and will set code P0273 if it detects low voltage. The check engine light will illuminate.
Is P0273 the same as a misfire code?
Not exactly. P0273 is an injector circuit fault, but it often triggers misfire codes like P0305 (cylinder 5 misfire) because of incorrect fuel delivery.