• | 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 provide an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Ignition 1 Voltage | P0201, P0202, P0203, P0204 | P0201, P0202, P0203, P0204 | -- | -- |
Injector 1 Control Circuit | P0201 | P0201 | P0201 | -- |
Injector 2 Control Circuit | P0202 | P0202 | P0202 | -- |
Injector 3 Control Circuit | P0203 | P0203 | P0203 | -- |
Injector 4 Control Circuit | P0204 | P0204 | P0204 | -- |
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 engine speed is greater than 700 RPM for Euro III Emissions or 600 RPM for Euro IV Emissions. |
• | The ignition 1 voltage is greater than 9 volts. |
• | The DTCs run continuously once the above conditions are met. |
The ECM detects the injector control circuit is open, shorted to voltage, or shorted to ground for more than 5 seconds.
DTCs P0201, P0202, P0203, P0204 are Type A DTCs.
DTCs P0201, P0202, P0203, P0204 are Type A DTCs.
J 34730-405 Injector Test Lamp
Important: The test lamp is used to load the circuit and may not illuminate.
⇒ | If less than B+, repair the ignition 1 voltage circuit of the fuel injector for a short to ground or an open/high resistance. |
⇒ | 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. |
Important: The engine coolant temperature (ECT) sensor must be between 10-32°C (50-90°F) in order for an accurate measurement.
⇒ | If the resistance is not within the specified range, replace the fuel injector. |
• | Perform the Diagnostic Repair Verification after completing the diagnostic procedure. |
• | Control Module References for engine control module replacement, setup, and programming |