OBD-II trouble code
P0257: Injection Pump Fuel Metering Control "B" Range/Performance (Cam/Rotor/Injector)
SAE J2012 APR2002: metering control B range/performance. No B performance monitor was in the P0251 reprints. The printed pair is diagnosis only.
Quick facts
- System
- Powertrain
- Category
- Fuel & Air
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $125 – $183 (check engine light diagnosis and testing, labor only; the fuel filter and the diesel injection pump are outside this pair)
- DIY difficulty
- Advanced DIY
Browse every code in P0200–P0299, or start from the full code library.
What does P0257 mean?
SAE J2012 APR2002 names P0257 Injection Pump Fuel Metering Control "B" Range/Performance (Cam/Rotor/Injector). Section 3.2 is an in-range value that is wrong for the conditions, including a stuck or skewed control. P0252 is that idea on letter A. P0258 and P0259 are B's low and high rows. A shorted wire is those rows, not this one.
Comparing channel B with channel A is useful only when the diagram shows two controls that the calibrator treats as the same part. The documents read do not establish that. The P0251 reprints describe one actuator. They do not give B a commanded-versus-actual window, and they do not say a healthy A reading is the spec for B. A filter is not established as this repair. RepairPal's $258–$322 filter average and the $2,630–$4,034 pump average were searched and left outside the diagnosis pair. The Ram 3500 pump page lists other year lines, which would be a further mismatch even if a pump had been the ordered part.
Do not open high-pressure fuel to compare two pumps that the diagram may not have. Depressurize before a low-pressure fitting is opened.
Common causes
- Metering control B stuck while the circuit is still in its normal range
- A skewed quantity result that section 3.2 allows without a circuit-low or circuit-high code
- Control B in range but not correct for the operating conditions
Symptoms
- P0257 stored
- An electrical test that passes while the performance complaint remains, which section 3.2 allows
- No quoted quantity error for channel B on this page
- P0252 stored on channel A, which is not this letter
Diagnostic steps
- 1.Confirm P0257, then find letter B on the diagram. A single actuator does not become B because A already has a performance code.
- 2.Open the B performance monitor in the service information. Do not substitute the P0251 PWM-mismatch sentence, and do not substitute A's actual reading as the limit.
- 3.Resistance, if that monitor asks for it, is connector off and ignition off. A normal result does not clear section 3.2.
- 4.Do not order the filter or the pump from the RepairPal averages that were searched. They are outside the pair.
- 5.Do not open a high-pressure fitting. Depressurize a low-pressure connection before it is opened.
- 6.The printed pair is diagnosis labor.
- 7.Verify with B's monitor recorded in the state it names. The driver does not watch the tool.
Repair cost
$125 – $183 (check engine light diagnosis and testing, labor only; the fuel filter and the diesel injection pump are outside this pair)
RepairPal's check engine light diagnosis and testing, updated 3 September 2026, is $125–$183 labor. The printed pair is that figure. A fuel filter is $258–$322 nationally and $249–$298 on a Ram 3500. A diesel injection pump is $2,630–$4,034 nationally and $3,384–$7,376 on the Ram 3500 line, which lists other year lines. All were searched and are outside the pair. No B-channel performance part was priced.
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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.