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 | P0201 | P0201 | -- |
Fuel Injector 2 Control | P0202 | P0202 | P0202 | -- |
Fuel Injector 3 Control | P0203 | P0203 | P0203 | -- |
Fuel Injector 4 Control | P0204 | P0204 | 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
Special Tools Required
J 44603 Injector Test Lamp
Circuit/System Testing
- Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement .
- Disconnect a fuel injector.
- With the ignition ON, engine OFF, probe the ignition 1 voltage circuit of the fuel injector with a test lamp that is connected to a good ground. The test lamp should illuminate.
- Remove the INJECTORS IGN MOD fuse.
- Measure the resistance between the INJECTORS IGN MOD fuse to the ignition 1 voltage circuit terminal of a fuel injector with a DMM. All wire circuit resistance should measure less than 2 ohms.
- Connect the J 44603 into each fuel injector connector one at a time. Crank the engine.
| ⇒ | If the test lamp does not illuminate, repair the open in the ignition 1 voltage circuit between the fuse and the splice. |
| ⇒ | If the resistance is more than 2 ohms, repair the high resistance in the ignition 1 voltage circuit. |
| ⇒ | If the test lamp flashes for each injector, perform the Fuel Injector Diagnosis. Refer to Fuel Injector Diagnosis . |
| ⇒ | If the test lamp does not flash for each injector, test for an open or a short to voltage in the control circuit of the fuel injector, an intermittent or poor connection at the engine control module (ECM). If the circuit tests normal, replace the control module. |
| ⇒ | If the test lamp remains illuminated at all times for any injector circuit, test for a short to ground in the control circuit of the fuel injector. If the circuit tests normal, replace the control module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM replacement, setup, and programming
