P268D: Cylinder 2 Injector Data Incompatible

P268D concerns the stored flow correction for the injector in cylinder 2. In GM's 2016 four-cylinder diesel table (16OBDG04) the test runs with ignition on and passes once the end-of-line injector adjustment (EIA) value has been written via DID $61; a missing value only counts as a failure when the manufacturer enable counter is zero, i.e. on a finished production controller. The code is Type A there and in GM's 2020 V8 diesel table. Where cylinder 2 physically sits depends on the maker's numbering. Ford's 2023 diesel summary also uses P268D. CARB wants the stored code to point to the injector with the wrong compensation, hence one code per cylinder.

Medium severity. Can I keep driving?Drive as little as possible and go to a repair shop. If you smell fuel or the engine is shaking badly, do not keep driving.

Cylinder 2 is numbered according to the manufacturer: check your engine's manual before working on it.

Symptoms

Check engine light on
Slight misfire feel or noise from cylinder 2

Most likely causes

Adjustment value of the cylinder 2 injector not programmed after replacement
Injectors moved between cylinders without updating codes
Programming session aborted (voltage drop, communication loss)

What to check, in order

Start with the simplest. You can tick off each step.

Check the connector and wiring of the injector indicated
Measure the resistance and compare it with the manufacturer's specification
Check the control signal with an oscilloscope; on direct injection or diesel engines, leave this to a repair shop because of the high voltages
On diesels, check the per-cylinder injection corrections

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P268D means

P: Powertrain: engine and transmission
2: Generic code: same on every make
6: Control modules and outputs
8D: Specific fault in that system

Frequently asked questions

Can I keep driving with code P268D?

Drive as little as possible and go to a repair shop. If you smell fuel or the engine is shaking badly, do not keep driving.

What causes code P268D?

The most common causes are: adjustment value of the cylinder 2 injector not programmed after replacement; injectors moved between cylinders without updating codes; programming session aborted (voltage drop, communication loss).

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.