Circuit Description
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 a higher than normal voltage for the commanded state of the driver, a diagnostic trouble code (DTC) will set.
DTC Descriptor
This diagnostic procedure supports the following DTCs:
| • | DTC P0262 Injector 1 Control Circuit High Voltage |
| • | DTC P0265 Injector 2 Control Circuit High Voltage |
| • | DTC P0268 Injector 3 Control Circuit High Voltage |
| • | DTC P0271 Injector 4 Control Circuit High Voltage |
Conditions for Running the DTC
| • | The engine speed is running. |
| • | The ignition 1 voltage is more than 9 Volts. |
| • | This DTC runs continuously once the above conditions are met. |
Conditions for Setting the DTC
The control module detects a short to voltage on the fuel injector control circuit.
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate when the diagnostic runs and fails. |
| • | The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn OFF after 4 consecutive ignition cycles in which the diagnostic runs without a fault. |
| • | DTCs can be cleared by using the scan tool. |
| • | Disconnect the ECM battery feed for more than 10 seconds. |
Diagnostic Aids
| • | 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 Connect 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 P0262, P0265, P0268, or P0271 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 flash? | Go to Step 6 | Go to Step 5 |
5 | 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 10 | Go to Step 7 |
6 | 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 10 | Go to Step 8 |
7 | 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 Repairsin Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 9 |
8 | Replace the affected fuel injector. Refer to Fuel Injection Fuel Rail Assembly Replacement . Did you complete the replacement? | Go to Step 10 | -- |
9 | Replace the ECM. Refer to Engine Control Module Replacement. Did you complete the replacement? | Go to Step 10 | -- |
10 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 11 |
11 | Are there any DTCs that have not been diagnosed? | System OK | |
