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. If the control module detects an incorrect voltage for the commanded state of the driver, a diagnostic trouble code (DTC) will set.
This diagnostic procedure supports the following DTCs:
• | DTC P0201 Injector 1 Control Circuit |
• | DTC P0202 Injector 2 Control Circuit |
• | DTC P0203 Injector 3 Control Circuit |
• | DTC P0204 Injector 4 Control Circuit |
• | The engine speed is more than 600 RPM. |
• | The ignition 1 voltage is more than 9 volts. |
• | This DTC runs continuously once the above conditions are met. |
• | The control module detects an incorrect voltage on the fuel injector control circuit. |
• | The above condition is met for 5 seconds. |
• | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
• | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. |
• | The control module turns OFF the malfunction indicator lamp (MIL) after 4 consecutive ignition cycles that the diagnostic runs and does not fail. |
• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
• | Clear the MIL and the DTC with a scan tool. |
• | Performing the Fuel Injector Coil Test may help isolate an intermittent condition. Refer to Fuel Injector Solenoid Coil Test . |
• | For an intermittent condition, refer to Intermittent Conditions . |
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Engine Controls? | Go to Step 2 | |
2 |
Does DTC P0201, P0202, P0203, or P0204 set? | Go to Step 4 | Go to Step 3 |
3 |
Did the DTC fail this ignition? | Go to Step 4 | Go to Diagnostic Aids |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 11 |
5 |
Does the test lamp flash? | Go to Step 9 | Go to Step 6 |
6 | Does the test lamp remain illuminated at all times? | Go to Step 8 | Go to Step 7 |
7 | Test the control circuit of the fuel injector for an open and for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 10 |
8 | Test the control circuit of the fuel injector for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
9 | Test for an intermittent and for a poor connection at the fuel injector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 12 |
10 | Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
11 |
Did you complete the repair? | Go to Step 14 | -- |
12 | Replace the affected fuel injector. Did you complete the replacement? | Go to Step 14 | -- |
13 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | Go to Step 14 | -- |
14 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 15 |
15 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK |