P0271
P0271-FUEL INJECTOR 4 CIRCUIT HIGH
- When Monitored:
With battery voltage greater than 10 volts, Main relay energized, and engine speed less than 3000 rpm.
- Set Condition:
The PCM detects that the Fuel Injector 4 input voltage is above the maximum acceptable value.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. DTC IS ACTIVE
NOTE: Diagnose and repair any system voltage or sensor reference voltage DTCs before continuing with this test.
1. Start the engine and allow it to reach normal operating temperature.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
2. With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking for an Intermittent DTC.
2. (K14) INJECTOR 4 CONTROL CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Fuel Injector 4 connector.
3. Disconnect the Powertrain Control Module (PCM) connector.
4. Turn the ignition on.
5. Measure the voltage of the (K14) Injector 4 Control circuit in the Fuel Injector 4 harness connector.
Is there any voltage present?
Yes
- Repair the (K14) Injector 4 Control circuit for a short to voltage.
- Perform the PCM Verification Test PCM Verification Test.
No
- Go To 3
3. (K14) INJECTOR 4 CONTROL CIRCUIT SHORTED TO (F343) FUSED Main OUTPUT 2 CIRCUIT
1. Measure the resistance between the (K14) Injector 4 Control circuit and the (F343) Fused Main Output 2 circuit in the Fuel Injector 4 harness connector.
Is the resistance above 100 ohms?
Yes
- Go To 4
No
- Repair the (K14) Injector 4 Control circuit for a short to the (F343) Fused Main Output 2 circuit.
- Perform the PCM Verification Test PCM Verification Test.
4. (K14) INJECTOR 4 CONTROL CIRCUIT OPEN OR HIGH RESISTANCE
NOTE: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.
1. Measure the resistance of the (K14) Injector 4 Control circuit between the Fuel Injector 4 harness connector and the Powertrain Control Module (PCM) harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 5
No
- Repair the (K14) Injector 4 Control circuit for an open circuit or high resistance.
- Perform the PCM Verification TestPCM Verification Test.
5. FUEL INJECTOR 4
1. Turn the ignition off.
2. Measure the resistance between the terminals of Fuel Injector 4.
NOTE: The resistance of the circuit will vary according to the temperature of the injector coil. Use the table below to determine the resistance range of the injector.
Is the resistance of the injector within the specified range?
Yes
- Go To 6
No
- Replace Fuel Injector 4.
- Perform the PCM Verification Test. PCM Verification Test.
6. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Injector 4 and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Search for any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM Verification Test PCM Verification Test.
No
- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test PCM Verification Test.