Circuit Description
The control module enables the appropriate fuel injector on the intake stroke for each cylinder. Ignition voltage is supplied directly to the fuel injectors. The control module controls each fuel injector by grounding the control circuit with a solid state device called a driver. The control module monitors the status of each driver. Each driver has a feedback voltage circuit which the engine control module (ECM) monitors. The injector control circuits are pulled-up to a voltage within the ECM . The ECM can determine if a control circuit is open, shorted to ground, or shorted to a voltage by monitoring the feedback voltage. If the ECM detects the control circuit voltage is too high when the circuit is commanded ON, this DTC sets.
DTC Descriptors
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 |
| • | DTC P0274 Injector 5 Control Circuit High Voltage |
| • | DTC P0277 Injector 6 Control Circuit High Voltage |
Conditions for Running the DTC
| • | The engine is operating. |
| • | The ignition 1 voltage is more than 10 volts. |
| • | DTC P0262, P0265, P0268, P0271, P0274, and P0277 run continuously once the above conditions are met . |
Conditions for Setting the DTC
| • | The ECM detects a short to voltage on a fuel injector control circuit. |
| • | The condition exists for more than 3 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
| • | The fuel injector control circuits connect to the ECM through 2 different in-line harness connectors. Both connectors are located at the front of the engine under the intake manifold. Connector C-119 contains 3 fuel injector control circuits and the ignition 1 voltage circuit. Connector C-118 contains 3 fuel injector control circuits. |
| • | If the condition is intermittent, refer to Intermittent Conditions . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if the condition is current.
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This step tests for a short to voltage on the fuel injector control circuit. If the voltage is more than the specified value, the circuit is shorted to a voltage or there is an internal ECM condition.
-
This step tests for a short to voltage on the fuel injector control circuit. , or at the connector C-119.
-
This step tests if the ignition 1 voltage supply circuit is shorted to the fuel injector control circuit.
Step | Action | Values | 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 | |
Is DTC P0262, P0265, P0268, P0271, P0274, or P0277 set? | -- | Go to Step 4 | Go to Step 3 | |
3 |
Did the DTC fail this ignition? | -- | Go to Step 4 | Go to Diagnostic Aids |
Important: The multi-way harness connectors, C118 and C119, are located under the intake manifold in front of the engine. Is the voltage more than the specified value? | 4.0 V | Go to Step 5 | Go to Step 6 | |
Test the control circuit of the fuel injector for a short to voltage between the multi-way harness connector and the ECM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9 | |
Does the DMM display OL? | -- | Go to Step 8 | Go to Step 7 | |
7 | Repair the short between the ignition 1 voltage supply circuit to the control circuit of the fuel injector. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 12 | -- |
8 | Test for shorted terminals and poor connections at the appropriate 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 12 | Go to Step 10 |
9 | Test for shorted terminals and poor connections 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 12 | Go to Step 11 |
10 | Replace the appropriate fuel injector. Did you complete the replacement? | -- | Go to Step 12 | -- |
11 | Replace the ECM. Refer to Engine Control Module Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- |
12 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 13 |
13 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |
