Circuit Description
The engine control module (ECM) enables the appropriate fuel injector on the intake stroke for each cylinder. Ignition voltage is supplied directly 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 ECM detects an incorrect voltage for the commanded state of the driver, a fuel injector control DTC sets.
Conditions for Running the DTC
| • | The engine speed is more than 40 RPM. |
| • | The system voltage is between 8-18 volts. |
Conditions for Setting the DTC
| • | The ECM detects an open on the fuel injector control circuit. |
| • | The condition exists for 30 seconds. |
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 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. |
Diagnostic Aids
| • | Performing the Fuel Injector Coil Test may help isolate an intermittent condition. Refer to Fuel Injector Solenoid Coil Test . |
| • | If the condition is intermittent, refer to Intermittent Conditions . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step verifies that the condition is present.
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This step verifies that the ECM is able to control the fuel injector. If the test lamp flashes, the control module and the wiring are OK.
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This step isolates the circuit between the multi-way connector and the control module. An open on the fuel injector control circuit will not allow the test lamp to flash.
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This step inspects for fuel injector harness damage between the multi-way connector and the intake plenum. Careful inspection may isolate the condition before removal of the intake plenum.
Step | Action | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | |||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |||||||
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Important: If DTCs P0201-206 are all set, inspect the ignition 1 voltage supply circuit for an open between the underhood bussed electrical center (UBEC) and the splice.
Does a fuel injector DTC set? | Go to Step 4 | Go to Step 3 | |||||||
3 |
Did the DTC fail this ignition? | Go to Step 4 | Go to Diagnostic Aids | ||||||
Does the test lamp flash while cranking the engine? | Go to Step 6 | Go to Step 5 | |||||||
Test the control circuit of the affected fuel injector for an open between the multi-way connector and the ECM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 12 | |||||||
6 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 13 | ||||||
Did you find and correct the condition? | Go to Step 16 | Go to Step 8 | |||||||
8 | Test for continuity between the ignition 1 voltage supply and the affected fuel injector control circuit, fuel injector side, at the multi-way connector with the DMM. Refer to Testing for Continuity in Wiring Systems. Does the DMM indicate OL? | Go to Step 9 | Go to Step 11 | ||||||
9 | Test the control circuit of the fuel injector for an open between the multi-way connector and the fuel injector connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 10 | ||||||
10 | Test the ignition 1 voltage supply circuit of the affected fuel injector for an open between the fuel injector and the splice. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 11 | ||||||
11 | 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 16 | Go to Step 14 | ||||||
12 | Test for an intermittent and for a poor connection at the 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 16 | Go to Step 15 | ||||||
13 | Repair the open in the ignition 1 voltage supply circuit of the fuel injector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 16 | -- | ||||||
14 | Replace the affected fuel injector. Refer to Fuel Injector and Fuel Rail Replacement . Did you complete the replacement? | Go to Step 16 | -- | ||||||
15 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | Go to Step 16 | -- | ||||||
16 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 17 | ||||||
17 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |||||||
