Powertrain, generic (extended)

P268B High Pressure Fuel Pump Calibration Not Learned/Programmed

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Common rail and direct-injection petrol systems use a high pressure pump whose delivery is trimmed by a metering or volume control valve. Where the pump comes with individual correction data, or the controller has to learn its behaviour, P268B reports that this data is missing or was never taught. No manufacturer documents P268B publicly; GM's diesel tables, which carry P268A and the per-cylinder injector codes, do not list it. CARB names pumps corrected by in-line resistors as an example of parts whose compensation must be checked from 2015 on. Rail pressure control may then work with a generic pump model, so pressure faults such as P0087 or P0088 and weak starting can follow.

Likely causes

Pump correction data not entered after pump replacement
Controller replaced or reflashed without transferring pump data
Pump variant does not match the software

Symptoms

  • Check engine light on
  • Long cranking or hard start
  • Reduced power with rail pressure deviations

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–400
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

high pressure pumpcontrol module

Related codes

P268AP0087P0088P0089P0090

References: law.cornell.edu, en.wikipedia.org.