Cylinder 5 Injector Circuit Low
The P0273 code means the vehicle's onboard diagnostic system has detected: Cylinder 5 Injector Circuit Low. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $100 - $450 (parts and labor)
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Common Symptoms
- Engine misfire on cylinder 5
- Rough idle on V6 or V8 engines
- Check Engine Light illuminated
- Reduced power
- Fuel smell from exhaust
Probable Causes (Ranked by Likelihood)
- Short to ground in cylinder 5 injector wiring Very High
- Faulty cylinder 5 fuel injector (shorted coil) High
- Corroded injector connector pins High
- Damaged wiring harness near cylinder 5 Moderate
- PCM injector driver circuit failure Low
Step-by-Step Diagnostic Procedure
-
Measure cylinder 5 injector resistance -- should be 11-18 ohms; below spec indicates a shorted coil
-
Check for short to ground between injector signal wire and engine ground with injector disconnected
-
Swap cylinder 5 injector with another cylinder and clear codes to isolate the fault
-
Inspect wiring harness routing near exhaust components for heat damage
-
Test PCM driver signal at cylinder 5 connector with a noid light
Frequently Asked Questions
Can I drive with code P0273?
You can drive short distances. On V6 and V8 engines, losing one cylinder is less noticeable than on a 4-cylinder, but the misfire still causes rough running and potential catalytic converter damage.
Where is cylinder 5 located?
Cylinder 5 location varies by engine configuration. On inline 6 engines, it is the fifth from the front. On V8 engines, it is typically the first cylinder on bank 2. Consult your service manual.
Can the code set if the injector is partially shorted?
Yes. A partially shorted coil will have lower than normal resistance, which the PCM detects as a low circuit condition even though the injector may still partially function.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P0273 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
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