OBD-II trouble code
P0260: Injection Pump Fuel Metering Control "B" Intermittent (Cam/Rotor/Injector)
There is no standard part called the "B" metering control — it means whatever second element that particular engine uses, and the candidates are physically unlike each other. Identify it from service data before ordering anything or opening anything, because guessing sends you to the wrong end of the engine.
Quick facts
- System
- Powertrain
- Category
- Fuel & Air
- Severity
- High severity
- Drivable
- No — stop driving until repaired
- Repair cost range
- $0 – $1,600
- DIY difficulty
- Advanced DIY
Browse every code in P0200–P0299, or start from the full code library.
What does P0260 mean?
The letter in this code is a slot, not a part number, and that is where most of the wasted effort on P0260 comes from. "A" is a reasonably safe assumption on any engine — it is the primary metering control on the injection pump. "B" is not safe to assume anything about, because manufacturers have used the designation for several genuinely different pieces of hardware, and they do not live in the same place, cost the same, or fail the same way.
On some applications "B" is a second complete injection pump, fitted to a V-configuration engine where each bank has its own. On others it is a second solenoid or actuator on a single pump, working alongside the first to control delivery over a wider range. On others again the manufacturer has assigned "B" to a spill control valve or a pressure control valve that regulates the same fuel by a different mechanism entirely. One of those is a component you can reach in twenty minutes; another sits in the valley of a V8 under the intake. Their parts prices differ by an order of magnitude. So the first hour of this job is not diagnostic at all: pull the service information for the specific engine, find out what the manufacturer means by "B", establish where it is, and only then decide what the work looks like. Skipping that step is how people end up quoting a pump on a vehicle whose fault is a valve, or removing an intake manifold to reach something that was accessible from underneath.
Once you know what it is, the fact that a second channel exists at all gives you the best capture tool in this family. Log commanded and actual fuel quantity for both channels side by side, with supply pressure alongside, and drive the route that has historically triggered the fault. When the event fires, the shape of that recording answers the question outright. If "B" drops away while "A" keeps tracking its command, the fault is confined to the "B" side — its harness, its connector, its ground, its actuator — and the shared tank, filter, transfer pump and common feed are all cleared in that one moment without a part being removed. If both traces wobble together at the same instant, the "B" channel is innocent and the cause is shared: supply volume, a common feed or relay, a shared ground, or the fuel itself. That distinction is what the single-channel version of this fault has to establish by elimination over days.
The symptom picture is also different from the single-channel case, and it is worth setting expectations with the owner. A vehicle that still has a working "A" channel does not usually stop when "B" drops out; it keeps running on what remains. What the driver reports is therefore a shudder, a lurch, a sudden loss of pulling power, or an imbalance that feels like a misfire, lasting a second or two before everything returns to normal. That is a real difference from the total cut a single-channel engine gives, and it matters diagnostically, because owners describing a brief roughness are often sent looking at glow plugs, injectors or turbo faults instead. It does not, however, make the fault benign — on the designs where "B" is a series element rather than a parallel one, a dropout still stops fuelling completely, which is why the identification step comes first.
On the physical side, the "B" component is nearly always the awkward one. It is the later addition, so it gets the leftover mounting position and the longer, more convoluted harness run to reach it. More length, more clips, more bends and more contact points is exactly the recipe for an intermittent, and it is why comparing the two connectors directly is so productive: side by side, a spread terminal, a lifted seal or the beginnings of corrosion on the "B" side is obvious in a way it never is when you are examining a single connector with nothing to judge it against.
One last caution on spending. Because the "B" component is usually the harder one to reach, a speculative replacement costs more in labour here than the same guess would on the "A" channel, and an intermittent that stays away for a fortnight afterwards proves nothing either way. Hold out for a captured event, a visible defect, or a measurement taken while the fault was actually present.
Common causes
- Misidentification of the "B" component, leading to work on the wrong hardware — the most common cause of wasted expense on this code
- Low-tension or spread terminal in the "B" actuator connector, which sits in the leftover mounting position and is often the less protected of the two
- Corrosion in the "B" connector that conducts in some conditions and not others
- Damage anywhere along the longer and more convoluted "B" harness run, which passes more clips and bends than the "A" run
- Heat-embrittled insulation cracking open at operating temperature
- Broken conductor strands inside intact insulation, opening only while the harness moves
- Water intrusion into the connector housing
- Shared feed, relay or ground fault affecting both channels, which a two-channel log identifies immediately
- Marginal lift or transfer pump output falling short only at peak demand
- "B" actuator sticking on deposits or wear
- "B" actuator coil breaking down when hot while reading normal on a cold resistance check
- Fuel waxing or gelling restricting supply below a certain temperature
Symptoms
- Check engine light that illuminates and later extinguishes itself, leaving P0260 stored or pending
- A brief shudder, lurch or loss of pulling power lasting a second or two, with normal running either side of it — the characteristic complaint where a working "A" channel keeps the engine going
- A roughness the owner describes as a misfire, which often sends the diagnosis toward glow plugs or injectors
- Sudden loss of fuelling or a stall on designs where the "B" element is in series rather than parallel
- Momentary limp mode that clears on the next key cycle
- Intermittent hard starting with no predictable pattern
- An occasional puff of black smoke during an episode
- Everything reading normal on a scan tool by the time the vehicle is inspected
- "B" commanded and actual fuel quantity diverging briefly in a data log while "A" continues tracking
- Fuel economy slightly down over a tank despite the engine feeling fine most of the time
Diagnostic steps
- 1.Before anything else, identify from service data what the manufacturer calls the "B" metering control on this specific engine — a second pump, a second solenoid on one pump, or a spill or pressure control valve — and where it is mounted. Cost, access and failure modes all follow from that answer.
- 2.Confirm whether the "B" element on this design works in parallel with "A" or in series with it, because that determines whether a dropout means rough running or a complete fuelling loss.
- 3.Set up a data log of commanded and actual fuel quantity for both channels plus supply pressure, then drive the route that has historically produced the fault.
- 4.Read the capture directly: "B" dropping out while "A" tracks confines the fault to the "B" side and clears every shared component at once; both channels moving together points at supply, a common feed, a shared ground or fuel quality.
- 5.Read and record the freeze frame and any earlier occurrences, and note whether the events cluster by temperature, load or road surface.
- 6.Compare the "B" connector directly against the "A" connector rather than assessing it alone. Side by side, a spread terminal, a lifted seal or early corrosion is immediately apparent.
- 7.Measure terminal tension in the "B" connector against a matching pin, since a terminal that has lost grip looks entirely normal in the housing.
- 8.Walk the full "B" harness run, which is the longer of the two, checking every clip and bend for rub marks and for stiff dark sections where heat has hardened the insulation.
- 9.Repeat wiggle testing at full operating temperature with data recording rather than on a cold engine in the bay.
- 10.Test the "B" actuator ground for voltage drop under load, and repeat while flexing the harness.
- 11.Measure fuel supply pressure under peak demand, and drain the water separator where the events are cold-weather only.
- 12.Do not order the "B" component until it has been correctly identified and a captured event, a visible defect or a live measurement points at it.
Repair cost
$0 – $1,600
The bottom of this range is genuinely zero, because some of these turn out to be a connector that needed cleaning and reseating. The distinctive cost risk on this code is not the repair, it is the identification: the hardware manufacturers call "B" ranges from an accessible external valve to a second complete injection pump, so an unverified assumption can be a four-figure mistake before any diagnosis has been done. Diagnostic time is typically $180-$400, above the "A"-channel equivalent because identifying the component on an unfamiliar engine takes time. Connector or terminal repair lands at $120-$400. Harness repair over the longer "B" run is $250-$750. A fuel filter, where events are cold-weather only, is $60-$220. A lift or transfer pump is $250-$900. A "B" fuel control actuator is $250-$1,100 installed, and considerably more where "B" turns out to be a second pump.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with diesel injection pump / fuel control actuator service 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.