P268A: Fuel Injector Calibration Not Learned/Programmed

P268A covers injector correction that relies on a learn routine rather than a printed code. GM's diesel tables 17OBDG04 to 19OBDG04A set it, Type A in one trip, when the small quantity learning (SQL) routine was not completed and stored before the vehicle left the assembly line. VW's 2014 Touareg 3.0 TDI (CNRB) lists it for a rail pressure deviation above 1,500–2,000 kPa lasting over 40 s. Audi's 2026 service note 2082225/1 reports it with the MIL on 2025–2026 A5 and Q5 2.0 TFSI petrol engines as a software issue. Deutz MD1 links it to a calibration fault of injector 1. Per-injector code faults use P268C–P2696. Symptoms range from none to rough idle and knock.

Symptoms

• Check engine light on
• Rough idle or louder combustion noise
• Often no noticeable change in driving

Most likely causes

• Injector quantity learn not completed after injector or controller replacement
• Engine control software fault (e.g. Audi 2.0 TFSI 2025–2026)
• Rail pressure deviation preventing correct learning
• Injector worn beyond the correction range

What to check, in order

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

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

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P268A means

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

Frequently asked questions

Can I keep driving with code P268A?

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 P268A?

The most common causes are: injector quantity learn not completed after injector or controller replacement; engine control software fault (e.g. Audi 2.0 TFSI 2025–2026); rail pressure deviation preventing correct learning.

Related codes

• P268BHigh Pressure Fuel Pump Calibration Not Learned/Programmed
• P2696Injector Data Incompatible
• P262AFuel Injector - Pilot Injection Not Learned
• P0087Fuel Rail/System Pressure - Too Low
• P0088Fuel Rail/System Pressure - Too High

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
• gsi.ext.gm.com: 17OBDG04 Engine Diagnostics
• static.nhtsa.gov: MC 10074008 2280

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.