GM Service Manual Online
For 1990-2009 cars only

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 P160C: Engine Calibration Information Not Programmed-GPCM

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

DTC P160C is a Type A DTC.

Conditions for Clearing the MIL/DTC

DTC P160C is a Type A DTC.

Reference Information

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. 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.
  2. If flow rate numbers are not present, refer to Fuel Injector Flow Rate Programming .
  3. Engine running, observe the DTC information with a scan tool. DTC P160C should not set.
  4. 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.