What Does P0274 Mean?
The ECM has detected an abnormally high voltage or current in the cylinder 5 fuel injector driver circuit. This indicates the injector on cylinder 5 is drawing more current than expected or there is a wiring fault feeding excessive voltage to the circuit. This code is found on engines with 5 or more cylinders. The driver may notice rough running, excessive smoke, or engine knock related to cylinder 5 overfueling.
Common Causes
35%
Short to voltage in the cylinder 5 injector wiring harness
30%
Cylinder 5 fuel injector with internal short circuit (reduced resistance)
15%
Corroded, melted, or damaged connector at the cylinder 5 injector
12%
ECM injector driver transistor failure for cylinder 5
8%
Harness routing issue causing the cylinder 5 wire to contact a voltage source
Diagnostic Steps
1
Measure cylinder 5 injector resistance at the connector — compare to manufacturer specifications. A significantly low reading (below minimum spec) confirms an internally shorted injector.
2
Disconnect the cylinder 5 injector and measure from each harness pin to B+ and ground to check for short circuits in the wiring — there should be no continuity to either.
3
Visually inspect the cylinder 5 injector connector and wiring for heat damage, fuel contamination, or chafing against engine components that could expose bare wire.
4
Monitor cylinder 5 injector current waveform with an oscilloscope and current clamp — compare the peak current, hold current, and ramp-down pattern to a known-good cylinder.
5
If all external tests pass, swap the cylinder 5 injector with another cylinder and clear codes — if the code follows the swapped injector, it has failed internally.
Estimated Repair Cost
$100 - $800
Parts + labor, varies by vehicle and location
The ECM has detected an abnormally high voltage or current in the cylinder 5 fuel injector driver circuit. This indicates the injector on cylinder 5 is drawing more current than expected or there is a wiring fault feeding excessive voltage to the circuit. This code is found on engines with 5 or more...
The most common cause of P0274 (Cylinder 5 Injector Circuit High) is: Short to voltage in the cylinder 5 injector wiring harness
Typical repair costs for P0274 range from $100 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A high injector circuit may cause overfueling on cylinder 5, leading to potential engine knock or exhaust system damage. Avoid heavy acceleration and high-load conditions until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0274 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel Injection System
Difficulty
Type
Generic (SAE)
Recommended Tools
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