Cylinder 12 Contribution/Balance Fault
Engine cylinder 12 is not contributing to engine power as expected.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
Inside the engine, cylinder 12 isn't firing properly, leading to a loss of power. This can happen if the fuel, air, or spark isn't right.
What the computer is actually seeing
The engine control module (ECM) monitors the performance of each cylinder. It measures parameters like voltage from the injectors (typically around 12V when operational) and crankshaft position. If cylinder 12 shows a significant difference in output compared to others, the ECM triggers this fault code.
What a healthy reading looks like
Cylinder contribution should be close to the average of other cylinders, ideally within 5-10% of the others' output.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Check the basic engine conditions: Ensure engine oil level is adequate and coolant level is normal.
- 2Inspect wiring and connectors to the injector and ignition coil of cylinder 12 for damage or corrosion.
- 3Use a scan tool to check live data for cylinder 12's fuel trim and compare it with other cylinders.
- 4Perform a compression test on cylinder 12. It should be between 120-200 psi depending on engine specs. If low, further investigation is needed.
- 5Swap the ignition coil and injector from cylinder 12 to another cylinder. Check if the fault moves with the component.
Common causes
- Faulty injector for cylinder 12
- Bad spark plug or ignition coil for cylinder 12
- Vacuum leaks affecting cylinder 12
- Low compression in cylinder 12
- Wiring issues or connector problems for cylinder 12
Typical repair cost
$$$
Related codes
Frequently asked questions
Can I drive with this code?
It's drivable but performance will be affected. Address it soon to prevent further damage.
Will this code come back if I clear it?
It can come back if the underlying issue isn't fixed.
Why do I see this code with a misfire code?
Cylinder contribution issues often cause misfires, and the ECM detects this discrepancy.
Working a real vehicle right now?
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