OBD-II trouble code
P0310: Cylinder 10 Misfire Detected
Cylinder 10 is missing combustion events. It is the highest-numbered cylinder production engines usually report individually, only a handful of twelve-cylinder applications going further — and on a V10 it means the end of a bank, which is the hardest place to reach.
Quick facts
- System
- Powertrain
- Category
- Ignition / Misfire
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $150 – $2,500
- DIY difficulty
- Advanced DIY
Browse every code in P0300–P0394, or start from the full code library.
What does P0310 mean?
P0310 is set when the engine controller attributes a repeated shortfall in crankshaft acceleration to cylinder 10. Only V10 and V12 engines have one. On a V10 it is the final cylinder in the numbering, which on most layouts places it at the rearmost position of its bank, and that position drives almost everything about how this repair goes.
The rearmost cylinder of a longitudinally mounted V10 sits against the bulkhead, under the cowl, behind the brake booster lines and the HVAC plumbing, frequently with a body brace over the top of it. In a motorhome or a bus chassis it may only be reachable through a doghouse from inside the cabin. Nothing about the fault is different from a misfire on cylinder 1; everything about the labour is. That gap between diagnostic cost and access cost is what makes the first move here so important.
That first move is the swap test, and it is worth more on this code than on almost any other misfire code in the range. A high-numbered cylinder always has same-bank neighbours running identical parts. Move the cylinder 10 ignition coil to a neighbouring cylinder, clear the codes, and drive. If the fault follows the part, the part is bad and you have proved it for nothing. If the fault stays with cylinder 10, you have eliminated the coil before paying to reach it. On an engine where reaching the cylinder is the expensive part of the job, proving what is wrong before you commit to the access is not a nicety, it is the whole strategy.
There is one more reason to slow down before ordering parts. A weak fuel supply can show up as a misfire on this cylinder. So can a plenum or runner gasket leaking at the rear corner, or an injector driver group starting to fail. Identify the cylinder with the relative-compression comparison and the injector check on this page — not by assuming the far end of the rail runs lean first. A single misfire on cylinder 10 still deserves a bank-level look at fuel pressure and vacuum before it is treated as a lone coil, because replacing the coil on a cylinder that is short of fuel will not fix anything.
Common causes
- Failed ignition coil or coil module on cylinder 10
- Worn or fouled spark plug, often long overdue because of the access
- Clogged or failed fuel injector
- Weak fuel supply that shows up as a misfire on this cylinder
- Vacuum or intake gasket leak at the rear corner of the bank
- Heat-damaged coil connector or chafed harness against the bulkhead
- Low compression from a burned exhaust valve or head gasket failure
- Exhaust manifold or header leak near the rear of the bank upsetting the oxygen sensor feedback for that bank
- Intake-valve carbon on a direct-injection engine
Symptoms
- Check engine light flashing while the misfire is active, steady afterwards
- Rough idle, most obvious at operating temperature
- Loss of power that appears under sustained load — towing, climbing, or a fully loaded motorhome on a grade
- Vibration felt through the floor rather than the steering wheel
- Noticeably worse fuel consumption
- Hesitation or surge at part throttle
- Bank-specific fuel trim drifting on a scan tool
Diagnostic steps
- 1.Confirm the cylinder numbering for your specific engine before planning any access. Manufacturers do not agree on this, and on a ten-cylinder engine an assumption costs an afternoon.
- 2.Do the swap test before anything is purchased. Move the cylinder 10 coil to a healthy same-bank cylinder, clear the codes and drive. A misfire that follows the coil ends the diagnosis at zero parts cost.
- 3.Check fuel trim by bank and log fuel rail pressure under load, not at idle. A weak supply can show up as a misfire on this cylinder. Identify it with the relative-compression comparison and the injector check, not by assuming the far end of the rail runs lean first. A driveway idle test will not show a supply that only sags under load.
- 4.Smoke-test the intake on the affected bank, paying particular attention to the rear runner and the back corner of the plenum gasket, where heat cycling opens leaks first.
- 5.Read all ten misfire counters together. Cylinder 10 alone is a component; cylinder 10 plus its immediate neighbours is a bank-level fuel or air problem; counters climbing across both banks is a global fault and this code is a symptom rather than the cause.
- 6.Inspect the coil connector and the harness where it passes the bulkhead. This is the hottest, most cramped run on the engine, and melted or chafed insulation here mimics a failed coil exactly.
- 7.Run a relative-compression comparison of cylinder 10 against the other cylinders, and check that cylinder's injector the way the service information specifies. Those two checks identify the cylinder. Do not assume the far end of the rail runs lean first. Only after ignition, fuel delivery and air have been checked should the cylinder come apart for mechanical work.
Repair cost
$150 – $2,500
Ordinary coil and plug parts are the low end. The rearmost cylinder of a V10 is not, because the cowl, brake-booster lines, HVAC plumbing or a body brace — and on a motorhome, the doghouse — decide the labor. An injector is next. A rear intake gasket on the affected bank is larger. Cylinder-head work starts beyond the top of the printed span. Insist on the swap test before any parts are approved. Those two figures are a planning band, not a quoted invoice. Add component prices to the time the service procedure allows for this chassis.
Estimate your repair
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Open the Repair Cost Estimator with ignition coil replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an advanced DIY job. It typically requires specialty tools, scan-tool access, lifting equipment, or careful sequencing to avoid causing new failures. Plan for extended downtime and have a backup vehicle. Most owners are better served by a shop that has done this repair before.