Diagnostic Instructions
DTC Descriptor
DTC P268A: Fuel Injector Calibration Data Not Programmed
Circuit/System Description
The control functions for the fuel injection system are integrated in the engine control module (ECM). During the manufacturing process, each injector's flow rate is measured and recorded as injection quantity adjustment (IQA) flow rate data. The flow
rate data is then etched as a hexidecimal number on the body of the injector. This data, together with the injector's cylinder position, is stored in the memory of both the glow plug control module (GPCM) and the ECM. When the ignition is turned ON, both the
GPCM and the ECM monitor to ensure that the fuel injection flow rate numbers are present. If any of the injector flow rate numbers are missing, the diagnostic for that control module will set the appropriate DTC.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The fuel injector IQA flow rate data is not programmed.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp
(MIL) on the second consecutive ignition cycle that the diagnostic runs and
fails. |
| • | The control module records the operating conditions at the time
the diagnostic fails. The first time the diagnostic fails, the control module
stores this information in the Failure Records. If the diagnostic reports
a failure on the second consecutive ignition cycle, the control module
records the operating conditions at the time of the failure. The control
module writes the operating conditions to the Freeze Frame and updates
the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL)
after 3 consecutive ignition cycles that the diagnostic runs and does
not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs
and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles,
if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Circuit/System Verification
- Review the Display ECM & GPCM Inj. Flow Rates parameter with a scan tool. All cylinders should be programmed with a flow rate number. Both the GPCM and the ECM should be programmed with the same flow rate numbers for the corresponding cylinders.
- Engine running, observe the DTC information with a scan tool. DTC P268A should not set.
- 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.
