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

Connector End View Reference

Description and Operation:

Fuel System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Special Tools Required

J 34730-405 Injector Test Lamp

Important: If you were sent here from Engine Cranks but Does Not Run, proceed to Circuit/System Testing.

1. Engine running, observe the DTC information with a scan tool. DTCs P0201, P0202, P0203, or P0204 should not set.
2. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

1. Ignition OFF, disconnect the harness connector of the appropriate fuel injector.
2. Ignition ON, verify that a test lamp illuminates between the ignition 1 voltage circuit 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. With the ignition OFF, connect a J 34730-405 between the control circuit and the ignition 1 voltage circuit.
4. Engine idling, the test lamp should flash.

⇒	If the test lamp remains ON all the time, test for a short to ground on the control circuit. If circuit/connections test normal, replace the ECM.

⇒	If the test lamp remains OFF all the time, test for a short to voltage or an open/high resistance on the control circuit. If circuit/connections test normal, replace the ECM.

5. If all circuits/connections test normal, test or replace 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.

1. Measure for 11-14 ohms of resistance between the terminals of the fuel injector.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.