OBD-II trouble code
P0287: Cylinder 9 Contribution/Balance Fault
A ninth cylinder means a V10 or V12 — a small, expensive population where parts are special-order and access is measured in half-days. That changes the method: on this engine you plan one teardown and test everything while you are in there.
Quick facts
- System
- Powertrain
- Category
- Fuel Injectors
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $4,000
- DIY difficulty
- Intermediate DIY
Browse every code in P0200–P0299, or start from the full code library.
What does P0287 mean?
This code is set by the module's crankshaft-based output comparison: each power stroke produces a measurable acceleration, the module compares them, and cylinder 9 came out below the allowed spread.
Before anything else, note what having a cylinder 9 tells you about the vehicle. Only ten- and twelve-cylinder engines have one — the Ford Triton V10, the Dodge and SRT V10s, the VW and Audi V10 petrol and TDI engines, BMW's V10, V10 and V12 exotics, and large industrial and marine diesels. If the engine in front of you has eight cylinders or fewer, the code has been misread or the manufacturer has reassigned it, and the manufacturer's own definition always outranks the generic one.
That population fact is not trivia. It changes how the job should be approached in three concrete ways.
First, there is often nothing to feel. On a ten- or twelve-cylinder engine each cylinder is under a tenth of total output, and the rotating assembly carries enough inertia to smooth over a deficit that would be obvious on a four. Owners routinely report nothing worse than slightly worse economy. The usual advice to reproduce the customer's complaint and work from it does not apply, because there frequently is no complaint — the scan data is the entire case. That cuts the other way too, and it is the reason not to dismiss the code: to be flagged at all against nine or eleven healthy peers, the deficit had to be substantial. A quiet engine here is a property of the layout, not evidence that the fault is small.
Second, parts are a planning problem rather than a shopping trip. Injectors, coils and plugs for these engines are frequently model-specific with limited aftermarket supply, and some are special-order with real lead times. That shifts the strategy away from buy-and-fit-to-find-out and toward substitution: swapping a suspect component with the equivalent from a known-good cylinder and seeing whether the fault follows costs nothing but labour and answers the question definitively. On a mainstream four-cylinder that technique is a nicety. Here it is often the only sensible route, and it is worth confirming price and availability before committing to any diagnosis that ends in a purchase.
Third, and most important to the customer's bill: access dominates everything. On a V10 or V12 the engine fills the bay, and reaching a rear-bank injector generally means the upper intake comes off and several hours go with it. The practical consequence is that you should treat the teardown as the expensive resource and plan around it. Once the intake is off, test every cylinder on that bank rather than only the one the code named — compression, leak-down, injector condition, plug condition — because a second visit costs the same access all over again. Doing all of it in one go is the difference between one bill and two, and on these engines that is a large difference.
As to what is actually limiting the cylinder, the module cannot tell you: fuel delivery, spark on petrol applications, and compression all look identical at the crankshaft. Read every stored code first, since an injector circuit code on the same cylinder means the problem is electrical and clears with the wiring repair. After that, the ordering is cheapest and most definitive first — plug and coil substitution, then compression and leak-down, and the injector last.
On diesel V10s the ignition branch drops out and the factory balance-rate figure becomes the primary evidence: a large, steady correction on cylinder 9 with healthy compression indicts that injector. Price it before you order. The VW and Audi V10 TDI pump-injector units are among the most expensive injectors fitted to any road vehicle, and the labour to reach them is not short.
Numbering varies as usual. Ford's Triton V10 numbers the passenger bank 1 through 5 and the driver's bank 6 through 10, putting cylinder 9 second from the rear on the driver's side. Other V10s use the odd-and-even bank split familiar from American V8s. Work from the engine's own diagram.
Common causes
- Restricted, worn or slow-opening cylinder 9 injector
- Low compression on cylinder 9 from worn rings, a burnt valve or a valvetrain fault
- Worn plug or a coil breaking down under load on petrol V10 and V12 applications
- Head gasket leaking between cylinder 9 and a neighbour or into the coolant jacket
- Low rail pressure, a restricted filter or contaminated fuel affecting that bank
- Weak high-pressure pump on a direct-injection or common-rail diesel
- Degraded injector spray pattern showing only under load
- Corroded or high-resistance connector at the cylinder 9 injector
- Intake plenum or runner gasket leak on that bank
- Code misread or manufacturer-reassigned on an engine with no ninth cylinder
Symptoms
- Check engine light with no drivability complaint at all, which is the most common presentation
- Slightly worse fuel economy as the only thing the owner has noticed
- Mild low-speed roughness that nine or eleven healthy cylinders largely conceal
- Reduced power under sustained load such as towing or a long climb
- Companion misfire codes such as P0300
- Hard starting or black smoke on diesel V10 applications
- Fuel trims skewed on the affected bank
- A fault that has been present for months because nothing prompted the owner to act
Diagnostic steps
- 1.Confirm the engine actually has a ninth cylinder. If it does not, the code has been misread or reassigned and the manufacturer's definition governs.
- 2.Read every stored code. An injector circuit code on cylinder 9 means the fault is electrical and repairing the circuit normally clears this code with it.
- 3.Accept that there may be no complaint to reproduce. On a ten- or twelve-cylinder engine one weak cylinder is under a tenth of output, so the scan data is the whole case and a road test will usually feel normal.
- 4.Run the balance or contribution test and record the size of the deviation. Against nine or eleven healthy peers, a flagged deviation is a substantial deficit rather than a marginal reading.
- 5.Price and check availability of the likely parts before planning the repair. On these engines components are often model-specific and special-order, which changes what a sensible diagnostic path looks like.
- 6.Prefer substitution over purchase. Swap the cylinder 9 plug, coil or injector with the equivalent from a known-good cylinder and see whether the fault follows — it costs labour instead of parts and answers definitively.
- 7.Plan the teardown as the expensive resource. Before removing the upper intake, write a list of everything to be tested while it is off.
- 8.Once you are in, test every cylinder on that bank rather than only cylinder 9 — compression, leak-down, injector and plug condition. A second visit costs the same access again.
- 9.Confirm which physical cylinder this engine calls number 9 from its diagram. The Triton V10 numbers the driver's bank 6 through 10; other V10s split odd and even across the banks.
- 10.On diesel applications, read the factory balance-rate figure for cylinder 9 and interpret it alongside compression before condemning the injector.
Repair cost
$100 – $4,000
Diagnosis is $100 to $220. The number that dominates this code is access, not parts: reaching a rear-bank cylinder on a V10 or V12 generally means the upper intake comes off, which is why testing everything on that bank in the same teardown is worth planning for. A plug or coil is $100 to $400 fitted. A port injector for a Triton V10 is $60 to $200 in parts plus 0.5 to 3 hours. Injectors for V10 and V12 exotics and direct-injection applications reach $250 to $700 each. Diesel V10 pump-injector units are the outlier — with labour, a single cylinder can approach four figures on its own. Supply-side repairs are $150 to $800, a high-pressure pump $600 to $1,800, and mechanical causes start near $1,500 and can exceed $4,000.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with fuel injector replacement preselected. Adjust labor rate and vehicle category to fit your situation.
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.