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 ECM detects a low voltage for the commanded state of the driver, DTC P0261, P0264, P0267, P0270, P0273, P0276, P0279, P0282 will set.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC P0261 Injector 1 Control Circuit Low Voltage |
| • | DTC P0264 Injector 2 Control Circuit Low Voltage |
| • | DTC P0267 Injector 3 Control Circuit Low Voltage |
| • | DTC P0270 Injector 4 Control Circuit Low Voltage |
| • | DTC P0273 Injector 5 Control Circuit Low Voltage |
| • | DTC P0276 Injector 6 Control Circuit Low Voltage |
| • | DTC P0279 Injector 7 Control Circuit Low Voltage |
| • | DTC P0282 Injector 8 Control Circuit Low Voltage |
Conditions for Running the DTC
| • | The engine speed is more than 40 RPM. |
| • | The system voltage is between 8-18 volts. |
| • | DTCs P0261, P0264, P0267, P0270, P0273, P0276, P0279, and P0282 run continuously once the above conditions have been met. |
Conditions for Setting the DTC
| • | The control module detects a low voltage condition on the fuel injector control circuit. |
| • | The above condition is met 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 |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Engine Control Module Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Is DTC P0261, P0264, P0267, P0270, P0273, P0276, P0279, or P0282 set? | Go to Step 3 | Go to Step 5 |
3 | Are DTCs P0261, P0267, P0273, and P0279 set at the same time? | Go to Step 11 | Go to Step 6 |
4 | Are DTCs P0264, P0270, P0276, and P0282 set at the same time? | Go to Step 12 | Go to Step 6 |
5 |
Did the DTC fail this ignition? | Go to Step 6 | Go to Diagnostic Aids |
6 |
Does the test lamp flash? | Go to Step 9 | Go to Step 7 |
7 | Does the test lamp remain illuminated at all times? | Go to Step 8 | 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 15 | Go to Step 14 |
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 15 | Go to Step 13 |
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 15 | Go to Step 14 |
11 | Repair the short to ground in the ignition 1 voltage circuit of the odd fuel injectors. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 15 | -- |
12 | Repair the short to ground in the ignition 1 voltage circuit of the even fuel injectors. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 15 | -- |
13 | Replace the affected fuel injector. Refer to Fuel Injector and Fuel Rail Replacement . Did you complete the replacement? | Go to Step 15 | -- |
14 | Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 15 | -- |
15 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 16 |
16 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
