OBD-II trouble code
P0265: Cylinder 2 Injector Circuit High
Cylinder 2 is the first cylinder whose location is genuinely ambiguous — cylinder 1 defines bank 1, but manufacturers disagree about where number two goes. On a transverse V engine it can be on the far bank, which changes the job from twenty minutes to most of a day.
Quick facts
- System
- Powertrain
- Category
- Fuel Injectors
- Severity
- Medium severity
- Drivable
- No — stop driving until repaired
- Repair cost range
- $50 – $1,500
- DIY difficulty
- Intermediate DIY
Browse every code in P0200–P0299, or start from the full code library.
What does P0265 mean?
The module switches an injector by grounding it. Voltage waits on one terminal, the module pulls the other to ground for a measured few milliseconds, and it watches to confirm the wire actually collapses toward zero while it does so. This code means it commanded the number two injector on and the circuit stayed high — either because there is no complete path to sink current through, or because something is holding the wire up at battery voltage.
That splits the causes into two groups. Open circuits: a broken conductor, a terminal that has backed out of the connector, or an injector coil that has failed open internally. And shorts to voltage: a chafed control wire touching a live circuit, which pins the line high no matter what the driver does. In both cases the cylinder receives no fuel, and its full charge of air goes out into the exhaust.
What sets this code apart from the cylinder 1 version has nothing to do with electricity. It is that cylinder 2 is the first cylinder on the engine whose position is genuinely open to question. Cylinder 1 is unambiguous — it defines bank 1 by convention, so wherever it is, it is on bank 1. Cylinder 2 has no such protection. On an inline engine it is simply the second from the front and there is nothing to debate. On a V engine there is plenty: some manufacturers number straight down one bank and only then cross over, which puts cylinder 2 immediately beside cylinder 1; others alternate from side to side, which puts cylinder 2 on the opposite bank entirely. Both conventions are in wide use and neither is more correct than the other.
That is not a trivia point, it is the single biggest cost variable on this repair. On a transverse V6 with alternating numbering, cylinder 2 can land on the rear bank against the firewall, where reaching the injector means removing the intake manifold and working blind over the back of the engine. The same part number, the same fault, and a bill several times larger. So look up the numbering diagram for the specific engine before quoting the work, before ordering anything and certainly before starting to take things apart. Working on the wrong bank is an expensive way to learn this.
There is a second, more useful consequence of cylinder 2's position, and it shows up in which codes arrive together. Many engines fire injectors in groups rather than individually, and the supply side is commonly split into pairs or banks — on a four-cylinder, one and four on one feed and two and three on the other is a widespread arrangement. If this code arrives on its own, look at cylinder 2's own wiring. If it arrives with a code for the cylinder that shares its feed, stop looking at injectors: two injectors do not fail open on the same afternoon, but one fuse, one relay contact or one splice in a shared supply does exactly that. Reading the code set rather than the code is what prevents someone from quoting two injectors for a single connector fault.
Because cylinder 2 is an interior cylinder rather than an end one, its lead sits within the main branch of the injector harness instead of at a corner of the engine. Damage there tends to be abrasion where the loom crosses a bracket or the intake, or heat where it has been dragged near the exhaust side, rather than fluid contamination from a leaking front cover.
As with any dead cylinder, do not drive it further than you must. Unburned mixture in a hot converter destroys it, and a flashing light means that is happening now.
Common causes
- Broken control wire between the module and the number two injector
- Terminal backed out or unseated in the injector connector
- Open winding inside the number two injector
- Control wire chafed against a bracket, intake or heat shield and shorted to a battery-voltage circuit
- Shared supply fault — fuse, relay contact or splice — affecting cylinder 2 and whichever cylinder shares its feed
- Harness abrasion where the main injector loom crosses a mounting point
- Heat damage where the loom has been rerouted too close to the exhaust side
- Damage during intake manifold removal on engines where cylinder 2 sits on the far bank
- Failed injector driver inside the module, which is uncommon and should be a measured conclusion
Symptoms
- Check engine light, flashing when the misfire is severe enough to endanger the converter
- A cylinder 2 misfire code stored alongside, with a strong shake at idle
- A second injector circuit code for the cylinder sharing the same supply, which points at the feed rather than at two injectors
- Noticeable loss of power and hesitation on acceleration
- Smell of unburned fuel from the exhaust
- Extended cranking and a rough start
- The fault appearing after intake manifold or upper engine work
- Idle that never smooths out regardless of engine temperature
Diagnostic steps
- 1.Look up the cylinder numbering diagram for this specific engine before touching anything. On a V engine cylinder 2 may be beside cylinder 1 or on the opposite bank, and that decision changes the whole job.
- 2.Read the full code set. A companion injector circuit code on the cylinder that shares this one's supply points at the shared feed, not at two failed injectors.
- 3.Check the injector supply fuse and, where fitted, the injector relay before assuming an individual circuit fault.
- 4.Inspect the injector connector and the section of main loom serving it for abrasion at brackets, and for heat damage where it runs near the exhaust side.
- 5.Unplug the injector and measure its coil resistance. An open or very high reading condemns it; a normal reading moves the search to the harness.
- 6.Check for battery voltage at the injector's supply terminal with the key on.
- 7.With both ends disconnected, check continuity of the control wire from the injector connector back to the module pin.
- 8.Check the control wire against ground with the key on and everything unplugged, to identify a short to battery voltage holding it high.
- 9.Where cylinder 2 sits on a rear or firewall bank, price the access honestly before committing, since intake removal dominates the labour.
- 10.Confirm the module is producing a drive pulse with a noid light or scan tool injector test before considering the driver circuit.
Repair cost
$50 – $1,500
Diagnosis is $75 to $150. A harness or connector repair is $100 to $300. The injector itself is $60 to $400 in parts, and the labour is where this code becomes unpredictable: on an inline engine or a front-bank position it is half an hour, while on a transverse V engine with cylinder 2 on the rear bank the intake manifold has to come off and three or more hours plus gaskets is realistic. Confirm which bank you are on before accepting a quote, because the same fault legitimately produces very different numbers. A module driver failure is uncommon at $500 to $1,500 with programming. Ignoring the code risks a converter at $500 to $2,500.
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.