GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Optra 🢒 Engine 🢒 Engine Controls - 1.6L (L91) 🢒 DTC P0261, P0264, P0267, or P0270

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 control module detects a lower than normal voltage for the commanded state of the driver, a diagnostic trouble code (DTC) will set.

DTC Descriptor

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

Conditions for Running the DTC
    • The engine is running.
    • The ignition 1 voltage is more than 9 Volts.
    • This DTC runs continuously once the above conditions are met.

Conditions for Setting the DTC

The control module detects an open or a short to ground on the fuel injector control circuit.

Action Taken When the DTC Sets
    • The malfunction indicator lamp (MIL) will illuminate when the diagnostic runs and fails.
    • The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.

Conditions for Clearing the MIL/DTC
    • The MIL will turn OFF after 4 consecutive ignition cycles in which the diagnostic runs without a fault.
    • DTCs can be cleared by using the scan tool.
    • Disconnect the ECM battery feed for more than 10 seconds.

Diagnostic Aids
    • Performing the Fuel Injector Coil Test may help isolate an intermittent condition. Refer to Fuel Injector Solenoid Coil Test .
    • For an intermittent condition, refer to Intermittent Conditions .

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

Connect 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?

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Go to Step 2

Go to Diagnostic System Check - Engine Controls

2
  1. Turn ON the ignition, with the engine OFF.
  2. Clear the diagnostic trouble code (DTC) with a scan tool.
  3. Start the engine.
  4. Observe the DTC Info with a scan tool.

Does DTC P0261, P0264, P0267, or P0270 set?

--

Go to Step 4

Go to Step 3

3
  1. Turn OFF the ignition for 30 seconds.
  2. Start the engine.
  3. Operate the vehicle within the Conditions for Running the DTC.

Did the DTC fail this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4
  1. Turn OFF the ignition.
  2. Disconnect the fuel injector.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 1 voltage circuit of the fuel injector with a test lamp that is connected to a good ground. Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 11

5
  1. Connect a test lamp between the control circuit and the ignition 1 voltage circuit of the fuel injector.
  2. Start the engine.

Does the test lamp flash?

--

Go to Step 7

Go to Step 6

6

Does the test lamp remain illuminated at all times?

--

Go to Step 9

Go to Step 8

7
  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage between the control circuit of the appropriate fuel injector, on the ECM side of the harness, to a good ground with a DMM.

Is the voltage within the specified range

3.4 V - 4.4 V

Go to Step 10

Go to Step 14

8

Test the control circuit of the fuel injector for an open and for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 11

9

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 11

10

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

11

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 Repairsin Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

12
  1. Repair the open or short to ground in the ignition 1 voltage circuit of the fuel injector. Refer to Wiring Repairs in Wiring Systems.
  2. Replace the fuse as necessary.

Did you complete the repair?

--

Go to Step 15

--

13

Replace the affected fuel injector. Refer to Fuel Injection Fuel Rail Assembly Replacement .

Did you complete the replacement?

--

Go to Step 15

--

14

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

--

Go to Step 15

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15
  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.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 16

16

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK