OBD-II trouble code
P0251: Injection Pump Fuel Metering Control "A" Malfunction (Cam/Rotor/Injector)
SAE J2012 APR2002: injection pump fuel metering control A. Two public reprints of a Chrysler P0251 chart disagree on what a bright test lamp means. The printed pair is the national diesel injection pump, and it is not every outcome.
Quick facts
- System
- Powertrain
- Category
- Fuel & Air
- Severity
- High severity
- Drivable
- No — stop driving until repaired
- Repair cost range
- $2,630 – $4,034 (national diesel injection pump replacement, parts and labor; one Chrysler reprint orders a pump only after a bright lamp flash, and another reprint does not; the Ram 3500 line, wiring, and an ECM are outside this pair)
- DIY difficulty
- Advanced DIY
Browse every code in P0200–P0299, or start from the full code library.
What does P0251 mean?
SAE J2012 APR2002 names P0251 Injection Pump Fuel Metering Control "A" (Cam/Rotor/Injector). The parenthetical is part of the published name. It is not a promise that the cam, the rotor, and the injector have all failed. P0252 is range/performance, P0253 is low, P0254 is high, and P0255 is intermittent. Section 3.8 leaves letter A to the manufacturer. Channel B starts at P0256.
Public reprints of a Chrysler chart titled P0251, CP3 pump regulator control, agree on a set condition: with the ignition on, the ECM sees a discrepancy between the PWM supplied to the electronic fuel control actuator and the PWM returned from it. They do not agree on the circuit numbers or on the lamp. One reproduction, igotacummins thread 3379, uses K604 as the driver and K65 as the return. Its step 1 connects an incandescent test light across those two circuits at the actuator connector, key on, engine off, and says the ECM self-test should flash the lamp brightly once, about 20 seconds later, compared with a lamp tied straight to the battery. On that copy a bright flash replaces the fuel pump, and no flash goes on to the wiring. Another reproduction, the dieseltruckresource thread step-10 lamp, uses the same K604 and K65 labels but puts the lamp at step 10, after the wiring, and a bright flash there goes to the intermittent-condition procedure while no flash replaces the ECM. A third write-up on dieseltruckresource uses K181 and K31. A bright lamp is therefore not a pump verdict and not an ECM verdict until the procedure in the service information for that VIN is the one in front of you.
Where those reprints do share a comparison, the direction matters. On an open-circuit check, resistance less than 10 ohms is the pass (the wire is intact) and anything else repairs the open. On a short between the two actuator wires, or a short to ground, or a short to another circuit, resistance less than 10 ohms is the fail. On a short to external voltage, voltage greater than 1 volt to battery negative is the fail. 'Less than 10 ohms' is not one meaning.
NHTSA MC-10212505, for 2019–2020 Ram 2500/3500 and 3500/4500/5500 chassis cabs with the 6.7L Cummins ETN, ETL, or ETM, lists P0087, P008A, and P0201 through P0206. It does not list P0251. Its fuel-quantity-solenoid inspection for metal is that bulletin's path, and it says not to flush high-pressure or low-pressure parts with Brakleen or a similar harsh solvent. Do not open a high-pressure fitting on the strength of P0251. Depressurize with the published procedure if a low-pressure connection has to come apart. High-pressure fuel can inject through skin.
Common causes
- A PWM command and a PWM return that do not match, which is the set condition the Chrysler reprints share
- A bright test-lamp flash read as a fuel-pump replacement because one reprint's step 1 says that, while another reprint's step 10 does not
- An open in the driver or the return, where less than 10 ohms is the pass on those reprints
- A short to ground or a wire-to-wire short, where less than 10 ohms is the fail
- Voltage greater than 1 volt to battery negative on the driver or the return, the external-voltage fail
- Circuit numbers K604/K65 taken from one reprint onto a truck whose chart prints K181/K31
- The 2019–2020 Ram metal-contamination repair, which MC-10212505 does not attach to P0251
Symptoms
- P0251 stored with the ignition on, which is when those reprints say the monitor runs
- A test lamp that flashes about 20 seconds after it is connected, with no agreed repair attached to that flash
- P0087 or P0201–P0206 stored, which can move a 2019–2020 Ram onto MC-10212505 instead
- P0253 or P0254 stored, which are the low and high rows rather than this malfunction row
Diagnostic steps
- 1.Use the service information for the VIN. The three public reprints do not agree on K604/K65 versus K181/K31, or on whether a bright lamp replaces the pump, goes to an intermittent test, or is followed by an ECM replacement.
- 2.If you are in a reprint that matches the VIN and it starts with the lamp, key on, engine off, actuator unplugged, incandescent lamp across driver and return. Compare the brightness with a lamp on the battery. Do not treat the flash as a pump order unless that VIN's step says so. The other reprint runs this lamp only after the wiring passes, and then a flash is the intermittent path.
- 3.Open-circuit checks: ignition off, module disconnected, end to end. Less than 10 ohms continues. Not less than 10 ohms repairs that open. Do the driver and the return as two measurements.
- 4.External voltage: each actuator wire to battery negative, greater than 1 volt repairs that short. Not greater than 1 volt continues. Driver and return are separate steps.
- 5.Shorts: less than 10 ohms between the two actuator wires, or from a wire to ground, or from a wire to another circuit at the module connector, is the fail on the reprints that use that sentence. Do not describe a short pass as 'under 10 ohms'.
- 6.Do not open the high-pressure side for this code. MC-10212505's solvent warning and metal inspection belong to the DTCs that bulletin lists. Depressurize before a low-pressure fitting is opened.
- 7.The printed pair is RepairPal's national diesel injection-pump average, because one reprint does order a pump. The Ram 3500 line is a different set of numbers and is outside the pair. An ECM replacement and a wiring repair are outside it too.
- 8.Verify with the powertrain verification test the chart names, not with a cleared code alone.
Repair cost
$2,630 – $4,034 (national diesel injection pump replacement, parts and labor; one Chrysler reprint orders a pump only after a bright lamp flash, and another reprint does not; the Ram 3500 line, wiring, and an ECM are outside this pair)
RepairPal's diesel injection pump replacement, updated 3 September 2026, is $2,630–$4,034 (labor $734–$1,076, parts $1,896–$2,958). The printed pair is that national average. The same publisher's Ram 3500 line is $3,384–$7,376, and that page lists other year lines, including $1,034–$1,182 for 2019 and 2020 and $3,288–$10,622 for several earlier years. Those lines are outside the pair. A fuel filter is $258–$322 nationally and $249–$298 on a Ram 3500, and no chart read orders the filter for P0251. Diagnosis is $125–$183 labor and is separate. Wiring and an ECM are not in the pump average.
Estimate your repair
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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.