Cylinder 4 Contribution/Balance Fault
The P0272 code means the vehicle's onboard diagnostic system has detected: Cylinder 4 Contribution/Balance Fault. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $150 - $1,200 (parts and labor)
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Common Symptoms
- Engine misfire on cylinder 4
- Rough idle and vibration
- Check Engine Light illuminated
- Uneven power delivery
- Engine shakes especially at idle
Probable Causes (Ranked by Likelihood)
- Faulty cylinder 4 fuel injector (incorrect fuel delivery) Very High
- Low compression in cylinder 4 High
- Leaking or clogged injector on cylinder 4 High
- Vacuum leak at cylinder 4 intake runner Moderate
- Worn camshaft lobe affecting cylinder 4 valves Low
Step-by-Step Diagnostic Procedure
-
Perform a cylinder contribution test using a scan tool to compare each cylinder's output
-
Run a compression test -- cylinder 4 should be within 10% of the highest cylinder
-
Swap cylinder 4 injector with another cylinder to determine if the injector is the cause
-
Check for vacuum leaks at cylinder 4 intake port using a smoke machine
-
If compression is low, perform a leak-down test to identify the failure point
Frequently Asked Questions
Can I drive with code P0272?
You can drive short distances with light loads. Cylinder 4 is producing less power than normal, and the engine will run rough. Avoid towing until repaired.
Is P0272 always a serious problem?
Not always. It could be as simple as a clogged injector that needs cleaning. However, low compression or a worn camshaft lobe would indicate a more serious mechanical issue requiring significant repair.
Can fuel quality cause a contribution fault?
Contaminated or low-quality fuel can cause injector clogging and uneven fuel delivery, which may trigger contribution codes. Using quality fuel and periodic injector cleaning can help prevent this.
Sources
This page is built from documented references. Verify against your own service info before repair work.
P0272 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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