The car drives perfectly. Can I ignore P0293?

That is exactly the wrong conclusion, and the reason is counter-intuitive. A balance monitor detects a weak cylinder by comparison, and a twelve-cylinder engine has so much rotational inertia — with each power stroke being such a small share of the total — that a deviation has to be relatively large before the monitor can see it at all. So the car feeling smooth is expected; a V12 hides a weak cylinder better than any other engine ever built. What it does not mean is that nothing is wrong. If anything, this code carries more weight on a V12 than the equivalent code on a four-cylinder, because the threshold it crossed was higher. Diagnose it while it is still one cylinder and not yet a catalytic converter.

Is this an injector problem?

Maybe, but the code does not say so and it is not the place to start. P0293 says cylinder 11 is producing less power than its neighbours; it does not say why. Three families of cause do that: fuel (a clogged, worn or leaking injector), ignition (a weak coil, a worn plug, a failing boot), and compression (a burnt valve, worn rings, a head gasket). Ignition is the cheapest and fastest to rule out, so check the plug and coil first — better still, swap them with another cylinder on the same bank and see whether the fault moves. Replacing a low-volume V12 injector to find out it was a spark plug is an expensive way to learn the order.

I also have P0296. Are two injectors bad?

That is possible but it is not the first thing to suspect. P0293 and P0296 are cylinders 11 and 12 — adjacent to each other at the same end of the same bank. That pattern is the classic signature of something shared: a head gasket leaking between two adjacent cylinders, an intake or plenum gasket failing at that end of the bank, or fuel distribution falling off at the far end of the rail. Two injectors failing at once in adjacent bores is a much rarer event than any of those. Do a relative compression test across all twelve cylinders and a fuel pressure test under load before you order parts — chasing two injectors on this pattern is a well-travelled way to spend a lot and fix nothing.

How long can I drive with it?

The engine will run and the car will drive, so this is not an immediate roadside emergency the way a hard circuit fault is. The risk is cumulative rather than sudden: a cylinder that is not burning its fuel properly sends the remainder into the exhaust, and over weeks that overheats and destroys a catalytic converter. On a V12 there are two of them, and they are not inexpensive. Treat it as something to diagnose in the next week or two rather than the next month or two, and avoid sustained high-load driving until you know what is causing it.

OBD-II trouble code

P0293: Cylinder 11 Contribution/Balance Fault

Cylinder 11 is producing measurably less power than the cylinders it is compared against. This is a performance code, not a wiring code — and on a twelve-cylinder engine, the fact that a balance monitor flagged it at all is stronger evidence than the same code would be on a small engine.

Medium severityPowertrainFuel InjectorsDrivable short-term

Quick facts

System: Powertrain
Category: Fuel Injectors
Severity: Medium severity
Drivable: Usually safe to drive short-term
Repair cost range: $100 – $5,000
DIY difficulty: Intermediate DIY

What does P0293 mean?

A contribution or balance monitor does not measure voltage. It measures work. The engine control module (ECM) watches crankshaft acceleration through each power stroke and compares what every cylinder contributes against what the others contribute. P0293 sets when cylinder 11's share falls consistently outside the acceptable window.

That distinction matters more than anything else on this page. P0291 and P0292 are circuit codes — they tell you the wiring is wrong. P0293 says the wiring may be perfectly fine and the cylinder is still not pulling its weight. Chasing wiring on a contribution code is one of the most common wasted afternoons in this whole family.

Here is the argument that should change how seriously you take it. A balance monitor works by comparison, and how easily it can see a weak cylinder depends on how much that cylinder matters to the whole. A twelve-cylinder engine carries enormous rotational inertia and fires twelve times per two revolutions, so each individual power stroke is a small share of the total — smaller than on any other production layout. That means the deviation on cylinder 11 had to be proportionally LARGE before the monitor could pick it out of the noise at all. The consequence cuts two ways and both are useful. First, the car may feel almost completely normal; a V12 is the smoothest engine layout ever built and it hides a weak cylinder better than anything else on the road. Second, and more importantly, this code on a V12 is therefore STRONGER evidence than the same code on a four-cylinder, not weaker. Do not dismiss it because the car drives beautifully. The monitor found something the seat of your pants cannot.

Three things make a cylinder weak, and they are worth separating cleanly because they are diagnosed differently and cost wildly different amounts. Fuel: a clogged, leaking, worn or electrically lazy injector delivering the wrong quantity. Ignition: a failing coil, a worn or fouled plug, a bad plug boot — on a gasoline V12 this is real, and it is the cheapest thing to eliminate. Compression: a burnt or tight valve, worn rings, a leaking head gasket, or a valvetrain problem. Order is everything. Verify ignition first because it is quick and inexpensive, then fuel, then compression. Going the other way around means paying for teardown to discover a spark plug.

One diagnostic shortcut is disproportionately valuable here: swap parts rather than replace them. Move the cylinder 11 coil and plug to another cylinder on the same bank and see whether the fault follows. If it does, you have found it for the cost of an hour. If it does not, you have eliminated ignition without buying anything. On a twelve-cylinder engine, where every part is a low-volume part and every teardown is expensive, that discipline is worth more than it is anywhere else.

Also read the code in company. P0293 by itself points at cylinder 11. P0293 alongside P0296 means cylinders 11 and 12 — adjacent, at the same end of the same bank — and that pattern is the signature of something SHARED rather than two coincidental failures: a head gasket leaking between adjacent cylinders, an intake or plenum gasket at that end of the bank, or fuel distribution failing at the far end of the rail. Contribution codes scattered across both banks point at whole-engine fuel supply instead.

The engine will still drive. The reason this is not a shrug is cumulative: a weak or misfiring cylinder sends unburned fuel into the exhaust, and over weeks that damages a catalytic converter that costs far more than whatever caused the code.

Common causes

Clogged, restricted, or worn cylinder 11 fuel injector delivering less fuel than commanded
Leaking or dribbling injector delivering fuel at the wrong time
Weak ignition coil, worn spark plug, or failing plug boot on cylinder 11 (gasoline engines — check this first, it is the cheapest to eliminate)
Low compression on cylinder 11 from a burnt or tight valve, worn rings, or a leaking head gasket
Intake manifold or plenum gasket leak at that end of the bank pulling unmetered air into the cylinder
Fuel rail pressure sagging at the far end of the rail under load
Carbon buildup on the intake valves restricting airflow, common on direct-injection V12s
Wiring or connector resistance high enough to shorten effective injector pulse without setting a circuit code

Symptoms

Check engine light on
Slight roughness at idle — often very subtle, because a V12 masks a weak cylinder better than any other layout
Reduced power, most often felt as the engine no longer pulling cleanly at the top of its range
Small drop in fuel economy
Occasional companion misfire codes such as P0300 if the cylinder gets weak enough to miss
Sometimes no symptom the driver notices at all — the monitor sees what the driver cannot

Diagnostic steps

1.Confirm your engine has an eleventh cylinder — only twelve-cylinder engines do — and confirm which physical cylinder the manufacturer calls number 11 from its own numbering diagram.
2.Read all stored codes and the freeze-frame data. P0293 together with P0296 means two adjacent cylinders at the same end of a bank, which points at a shared cause rather than two separate failures.
3.Take this code seriously even if the car drives beautifully. A twelve-cylinder engine has so much rotational inertia that the deviation had to be large before the monitor could flag it at all.
4.Check ignition first on a gasoline engine because it is fast and cheap: inspect the cylinder 11 plug, coil and boot, and compare them against their neighbours.
5.Swap the cylinder 11 coil and plug with another cylinder on the same bank, clear the code, and drive. If the fault follows the parts, you have found it without buying anything.
6.View live injector data and per-cylinder contribution or balance values with a capable scan tool, and compare cylinder 11 against the rest of its bank.
7.Test fuel rail pressure under load, not just at idle. Cylinder 11 sits toward the far end of its rail, and a distribution weakness shows there first.
8.Run a relative compression test across all twelve cylinders in one capture — it is the single highest-value test on this engine and it separates a mechanical problem from a fuel or ignition one before any teardown.
9.If compression is confirmed low, follow with a cylinder leak-down test to identify where it is escaping: valves, rings, or head gasket.
10.Inspect for intake or plenum gasket leaks at that end of the bank, and on direct-injection engines assess intake valve carbon buildup.
11.Only condemn the injector after ignition and compression have both been cleared, since a twelve-cylinder injector is a low-volume part and reaching it is not quick.

Repair cost

$100 – $5,000

If it turns out to be ignition, a plug and coil on one cylinder is usually $100-$400 including labor and is by far the best outcome. A fuel injector on a twelve-cylinder engine is $150-$700 in parts plus 1.5-5 hours of labor depending on access, and many shops recommend replacing a bank's worth at once because the labor to get back in is the expensive part. A fuel rail pressure problem is $200-$900. Mechanical repairs are what push the ceiling: a head gasket, valve job or ring problem on a V12 runs $2,000-$5,000 and up, because everything on top of the engine has to come off to get there. Diagnosis alone is typically $120-$250, and on this engine it is money well spent — the order you test in decides which end of this range you land on.

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DIY vs shop

This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.