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 Descriptors

DTC P0201 00

Cylinder 1 Injector Control Circuit Malfunction

DTC P0202 00

Cylinder 2 Injector Control Circuit Malfunction

DTC P0203 00

Cylinder 3 Injector Control Circuit Malfunction

DTC P0204 00

Cylinder 4 Injector Control Circuit Malfunction

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Fuel Injector Positive Voltage Control Group 1	-	P0201 00, P0204 00	-	-
Fuel Injector Positive Voltage Control Group 2	-	P0202 00, P0203 00	-	-
Fuel Injector 1 Control	P0261 00	P0201 00	P0262 00	-
Fuel Injector 2 Control	P0264 00	P0202 00	P0265 00	-
Fuel Injector 3 Control	P0267 00	P0203 00	P0268 00	-
Fuel Injector 4 Control	P0270 00	P0204 00	P0271 00	-

Circuit/System Description

The engine control module (ECM) supplies voltage to each fuel injector on the injector positive voltage control circuits. The ECM energizes each fuel injector by grounding the control circuit of that fuel injector. The ECM monitors the status of the injector positive voltage control circuits and the fuel injector control circuits. The injectors are separated into the following two groups:

•	Group 1 - Injectors 1 and 4

•	Group 2 - Injectors 2 and 3

When a fuel injector circuit condition is detected by the ECM, the affected fuel injector will be disabled and may disable the affected group of fuel injectors.

Conditions for Running the DTC

•	The engine is running.

•	The ECM monitors for a condition once per camshaft revolution.

Conditions for Setting the DTC

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match.

Action Taken When the DTC Sets

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

Conditions for Clearing the DTC

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

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1.	Ignition ON, check the diagnostic trouble code (DTC) information with a scan tool. DTC P2146 or P2149 are not set.

2.	If any DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.

3.	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 are captured in the Freeze Frame/Failure Records Data List.

Circuit/System Testing

Static Test

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

2.	Ignition ON, test for 5.8-7.8 V between the low control circuit terminal 2 and ground.

3.	If less than the specified range, test the low control circuit for an open/high resistance or for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

4.	If greater than the specified range, test the low control circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

5.	Ignition ON, connect a test lamp between the affected fuel injector low control circuit terminal 1 and ground.

6.	Engine cranking or running, the test lamp should illuminate or flash.

7.	If the test lamp does not illuminate or flash, replace the K20 Engine Control Module.

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

Component Testing

Static Test

1.	Disconnect the harness connector at the affected fuel injector.

2.	Note The DMM and test leads must be calibrated to 0 Ω in order to prevent misdiagnosis. Test for 0.2-0.7 Ω between the low control terminal 2 and the high control terminal 1.

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

4.	Test for infinite resistance between each terminal and ground.

5.	If not the specified value, replace the fuel injector.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Fuel Injector Replacement (LBY/A20DTR) Fuel Injector Replacement (LBS/A20DTH)

•	Control Module References for ECM replacement, programming and setup