GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2007 🢒 Isuzu MD F-Series 🢒 Engine 🢒 Engine Controls and Fuel - 7.8L (LF8) 🢒 DTC P268A

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P268A: Fuel Injector Calibration Data Not Programmed

Circuit/System Description

The electrically erasable & programmable read only memory (EEPROM) memorizes fuel injector flow rate information. If the engine control module (ECM) detects fuel injector flow rates are not programmed into the ECM or an error in the programmed fuel injector flow rates, this DTC will set.

Conditions for Running the DTC

The ignition switch is ON.

Conditions for Setting the DTC

Either of following condition is met:

    • The ECM detects that the fuel injector flow rate is not programmed.
    • The ECM detects an error in the programmed fuel injector flow rate.

Action Taken When the DTC Sets

DTC P268A is a Type A DTC.

Conditions for Clearing the DTC

DTC P268A is a Type A DTC.

Diagnostic Aids

Inspect for any recent engine mechanical repairs. An incorrectly installed IAT sensor 2 will cause this DTC to set.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Engine Control Module Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Engine Control Module Connector End Views

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification

Important: Determine the ambient temperature by using an accurate thermometer.

  1. Review the Display Injector Flow Rates parameter with a scan tool. All cylinders should be programmed with a flow rate number. The ECM should be programmed with the same flow rate numbers for the corresponding cylinders.
    2. ⇒If flow rate numbers are not present, refer to Fuel Injector Flow Rate Programming.
  2. Engine running, observe the DTC information with a scan tool. DTC P268A should not set.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.