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. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Ignition 1 Voltage - Fuse to Splice | ¹ | ² | -- | -- |
Ignition 1 Voltage - Splice to Injector | ¹ | P0201, P0202, P0203, or P0204 | -- | -- |
Fuel Injector 1 Control | P0201, P0300 | P0201, P0300 | P0201 | -- |
Fuel Injector 2 Control | P0202, P0300 | P0202, P0300 | P0202 | -- |
Fuel Injector 3 Control | P0203, P0300 | P0203, P0300 | P0203 | -- |
Fuel Injector 4 Control | P0204, P0300 | P0204, P0300 | P0204 | -- |
¹Open fuse, cranks no start ²Cranks no start | ||||
Circuit/System Description
The control module enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied to the fuel injectors. The control module controls each fuel injector by grounding the control circuit via a solid state device called a driver.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Special Tools
J 44603 Injector Test Lamp
For equivalent regional tools, refer to Special Tools.
Circuit/System Verification
- Engine idling, observe the following control circuit status parameters for each fuel injector:
- Engine running, observe the DTC information with a scan tool. DTCs P0201, P0202, P0203, or P0204 should not set.
- 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.
| • | INJ Ckt Short Gnd Test Status |
| • | INJ Ckt Open Test Status |
| • | INJ Ckt Short Volts Test Status |
| Each parameter should display OK or Not Run. |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at a fuel injector.
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal A and ground.
- Ignition OFF, connect a J 44603 Injector Test Lamp between the control circuit terminal B and the ignition circuit terminal A of each fuel injector one at a time.
- Engine cranking, the test lamp should flash for each injector.
- If all circuits test normal, test or replace the fuel injector. Refer to Fuel Injector Diagnosis.
| ⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test or replace the fuel injector. |
| ⇒ | If the test lamp is always ON, test the appropriate control circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module (ECM). |
| ⇒ | If the test lamp is always OFF, test the appropriate control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for replacement, setup, and programming |
