GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 STS 🢒 Engine 🢒 Engine Controls - 4.6L (LH2) 🢒 DTC P0262, P0265, P0268, P0271, P0274, P0277, P0280, or P0283

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 high voltage for the commanded state of the driver, DTC P0262, P0265, P0268, P0271, P0274, P0277, P0280, P0283 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
    • DTC P0280 Injector 7 Control Circuit High Voltage
    • DTC P0283 Injector 8 Control Circuit High Voltage

Conditions for Running the DTC
    • The engine speed is more than 40 RPM.
    • The system voltage is between 8-18 volts.
    • DTCs P0262, P0265, P0268, P0271, P0274, P0280, and P0283 run continuously once the above conditions have been met.

Conditions for Setting the DTC
    • The ECM detects a high 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

  1. Clear the DTCs with a scan tool.
  2. Start the engine.
  3. Observe the DTC Info with a scan tool.

Is DTC P0262, P0265, P0268, P0271, P0274, P0277, P0280, or P0283 set?

Go to Step 4

Go to Step 3

3

  1. Observe the Freeze Frame/Failure Records data for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 4

Go to Diagnostic Aids

4

  1. Turn OFF the ignition.
  2. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .
  3. Disconnect the affected fuel injector.
  4. Probe the control circuit of the fuel injector with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems.
  5. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 5

Go to Step 6

5

Test the control circuit of the fuel injector 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 8

Go to Step 6

6

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 8

Go to Step 7

7

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 8

--

8
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 9

9

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