The fuel 1 injector drive circuit is a high-voltage supply and drives injectors installed to cylinders 1, 2, and 3. The engine control module (ECM) steps up the battery voltage and supplies the resulted high voltage to the related injectors continuity. If the fuel 1 injector drive circuit supply to cylinder 1, 2, or 3 is short to ground circuit or if the injector solenoid control circuit 1, 2, or 3 is short to ground, this DTC will set.
This diagnostic procedure supports the following DTC:
DTC P1263 Injector Positive Voltage Control Circuit Group 1 Low Voltage
• | The ignition switch is ON. |
• | The battery voltage is between 10-16 volts. |
• | The engine is running. |
• | The crankshaft position (CKP) sensor is not failed. |
The ECM detects that the injector power supply circuit is short to ground circuit.
• | The ECM illuminates the malfunction indicator lamp (MIL) and reduced engine power indicator lamp, if fitted, when the diagnostic runs and fails. |
• | The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records. |
• | The ECM disables 1, 2, and 3 injector operation. |
• | The ECM limits fuel injection quantity for fail-safe operation. |
• | The ECM closes the exhaust gas recirculation (EGR) valve and holds to close position. |
• | The ECM limits fuel rail pressure for fail-safe operation. |
• | The ECM limits acceleration operation range. |
• | The ECM inhibits the PTO control. |
• | The ECM inhibits cruise control. |
• | The MIL resets when the ignition is turned OFF. |
• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
• | Clear the MIL and the DTC with a scan tool. |
Step | Action | Values | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||
2 |
Does the DTC fail this ignition? | -- | Go to Step 3 | Go to Intermittent Conditions | ||||
3 |
Are the all resistance measures less than specified value? | 2 ohms | Go to Step 4 | Go to Step 6 | ||||
4 |
Are the resistance measures more than the specified value? | 10Mohms | Go to Step 5 | Go to Step 6 | ||||
5 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 | ||||
6 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 7 | ||||
7 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 8 | ||||
8 |
Are all resistance measures less than specified value? | 2 ohms | Go to Step 9 | Go to Step 11 | ||||
9 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Intermittent Conditions | ||||
10 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 | ||||
11 | Replace the appropriate injector. Refer to Fuel Injector Replacement and Fuel Injector Flow Rate Programming . Did you complete the replacement? | -- | Go to Step 13 | -- | ||||
12 |
Important: The replacement ECM must be programmed. Replace the ECM. Refer to Engine Control Module Programming and Setup , Engine Control Module Replacement/Restore Fuel Rate Data , and Fuel Injector Flow Rate Programming . Did you replacement? | -- | Go to Step 13 | -- | ||||
13 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 14 | ||||
14 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK |