Diagnostic Instructions

DTC Descriptors

DTC P0261: Injector 1 Control Circuit Low Voltage

DTC P0262: Injector 1 Control Circuit High Voltage

DTC P0264: Injector 2 Control Circuit Low Voltage

DTC P0265: Injector 2 Control Circuit High Voltage

DTC P0267: Injector 3 Control Circuit Low Voltage

DTC P0268: Injector 3 Control Circuit High Voltage

DTC P0270: Injector 4 Control Circuit Low Voltage

DTC P0271: Injector 4 Control Circuit High Voltage

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Ignition 1 Voltage	P0261, P0264, P0267, P0270	P0261, P0264, P0267, P0270	--	--
Injector 1 Control Circuit	P0261	P0261	P0262	--
Injector 2 Control Circuit	P0264	P0264	P0265	--
Injector 3 Control Circuit	P0267	P0267	P0268	--
Injector 4 Control Circuit	P0270	P0270	P0271	--

Circuit/System Description

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.

Conditions for Running the DTC

Conditions for Setting the DTC

P0261, P0264, P0267, or P0270

The ECM detects the injector control circuit is open or shorted to ground.

P0262, P0265, P0268, or P0271

The ECM detects the injector control circuit is shorted to voltage.

Action Taken When the DTC Sets

DTC P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271 are Type A DTCs.

Conditions for Clearing the DTC

DTC P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271 are Type A DTCs.

Reference Information

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

Circuit/System Verification

1. Engine running, observe the DTC information with a scan tool. DTC P0261, P0262, P0264, P0265, P0267, P0268, P0270, or P0271 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 Data List.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the appropriate fuel injector.

Important: The test lamp is used to load the circuit and may not illuminate.

2. Connect a test lamp between the ignition 1 voltage circuit of the fuel injector and ground.
3. Command the fuel pump relay ON with a scan tool and load test for battery voltage between the ignition 1 voltage circuit of the fuel injector and ground.

⇒	If less than B+, repair the ignition 1 voltage circuit of the fuel injector for a short to ground or an open/high resistance.

4. With the ignition OFF, connect a J 34730-405 Injector Test Lamp between the control circuit and the ignition 1 voltage circuit of the fuel injector.
5. Engine running, 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.

6. If all circuits/connections test normal, test or replace the fuel injector.

Component Testing

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.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.