The engine control module (ECM) enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The ECM controls each fuel injector by grounding the control circuit via a solid state device called a driver. The ECM monitors the status of each driver.

The ECM detects the injector control circuit is open, shorted to voltage, or shorted to ground for greater than 5 seconds.

DTCs P0201, P0202, P0203, P0204 are Type A DTCs.

DTCs P0201, P0202, P0203, P0204 are Type A DTCs.

Schematic Reference

Engine Controls Schematics

Description and Operation

Fuel System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools Required

J 34730-405 Injector Test Lamp

1. Engine running, observe the DTC information with a scan tool. DTCs P0201, P0202, P0203, or P0204 should not set.
2. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the appropriate fuel injector.
2. Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit terminal 1 and ground.

⇒	If the test lamp does not illuminate, repair the ignition 1 voltage circuit for a short to ground or an open/high resistance. Replace the fuse if necessary.

3. Ignition OFF, connect a J 34730-405 between the control circuit terminal 2 and the ignition 1 voltage circuit terminal 1.
4. Engine running, the test lamp should flash.

⇒	If the test lamp is always ON, test the control circuit for a short to ground. If circuit tests normal, replace the ECM.

⇒	If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the ECM.

5. If all circuits test normal, test or replace the fuel injector.

1. Ignition OFF, disconnect the harness connector at the fuel injector.

Important: The engine coolant temperature (ECT) sensor must be between 10-32°C (50-90°F) in order for an accurate measurement.

2. Test for 11-14 ohms of resistance between the ignition 1 voltage terminal 1 and the control terminal 2.

⇒	If not within the specified range, replace the fuel injector.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.