GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Epica 🢒 Engine 🢒 Engine Controls - 2.5L (LBK) 🢒 DTC P0261, P0264, P0267, P0270, P0273, or P0276

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 low when the circuit is commanded ON, this DTC sets.

DTC Descriptors

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
    • DTC P0273 Injector 5 Control Circuit Low Voltage
    • DTC P0276 Injector 6 Control Circuit Low Voltage

Conditions for Running the DTC
    • The engine is operating.
    • The ignition 1 voltage is more than 10 volts.
    • DTC P0261, P0264, P0267, P0270, P0273, and P0276 run continuously once the above conditions are met .

Conditions for Setting the DTC
    • The ECM detects an open or short to ground on a fuel injector 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.

  1. This step determines if the condition is current.

    2.

  2. This step tests for an open or a short to ground in the ignition 1 voltage circuit between the fuse and the splice.

    3.

  3. This step tests for an open or high resistance on the fuel injector control circuit, between the harness connector and the ECM, or an internal ECM condition.

    4.

  4. This step tests for a short to ground on the fuel injector control circuit, between the harness connector and the ECM, or an internal ECM condition.

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

Go to Diagnostic System Check - Engine Controls

2
  1. Turn ON the ignition, with the engine OFF.
  2. Clear the DTCs with a scan tool.
  3. Attempt to start the engine.
  4. Observe the DTC Info with a scan tool.

Is DTC P0261, P0264, P0267, P0270, P0273, or P0276 set?

--

Go to Step 3

Go to Step 4

3

Are DTCs P0261, P0264, P0267, P0270, P0273, and P0276 set at the same time?

--

Go to Step 10

Go to Step 5

4
  1. Observe the Freeze Frame/Failure Records 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 5

Go to Diagnostic Aids

5
  1. Turn OFF the ignition.

    2. Important: The multi-way harness connectors, C118 and C119, are located under the intake manifold in front of the engine.

  2. Disconnect the appropriate fuel injector multi-way harness connector.
  3. Probe the control circuit of the appropriate fuel injector, engine control module (ECM) side of harness, with a test lamp connected to B+.
  4. Crank the engine.

Does the test lamp flash while cranking the engine?

--

Go to Step 6

Go to Step 7

6
  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage between the control circuit of the appropriate fuel injector, ECM side of harness, to a good ground with a DMM.

Is the voltage within the specified range?

3.4 - 4.4V

Go to Step 8

Go to Step 16

7
  1. Test the control circuit of the appropriate fuel injector between the multi-way harness connector and the ECM, for one of the following conditions:
    2. • An open
    • Short to ground
    • High resistance
  2. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 12

8
  1. Remove the intake manifold. Refer to Intake Manifold Replacement Intake Manifold Replacement - in Engine Mechanical 2.5L (LBK).
  2. Test the control circuit of the appropriate fuel injector for one of the following conditions:
    3. • An open
    • A short to ground
    • High resistance
  3. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 9

9

Test for an open or for high resistance on the ignition 1 voltage circuit of 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 17

Go to Step 11

10
  1. Turn OFF the ignition.

    2. Important: The multi-way harness connectors, C118 and C119, are located under the intake manifold in front of the engine.

  2. Disconnect the appropriate fuel injector multi-way harness connector.
  3. Probe the ignition 1 voltage circuit, fuel injector side of harness, with a test lamp connected to B+.

Does the test lamp illuminate?

--

Go to Step 13

Go to Step 14

11

Test for an intermittent and for a poor connection 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 17

Go to Step 15

12

Test for an intermittent and for a poor connection 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 17

Go to Step 16

13
  1. Remove the intake manifold. Refer to Intake Manifold Replacement Intake Manifold Replacement - in Engine Mechanical 2.5L (LBK).
  2. Repair the ignition 1 voltage circuit of the appropriate fuel injector for a short to ground between the multi-way harness connector and the fuel injectors. Refer to Wiring Repairs in Wiring Systems.
  3. Replace the fuse as necessary.

Did you complete the repair?

--

Go to Step 17

--

14
  1. Repair the ignition 1 voltage circuit of the fuel injectors for an open or a short to ground between the multi-way harness connector and the fuse. Refer to Wiring Repairs in Wiring Systems.
  2. Replace the fuse as necessary.

Did you complete the repair?

--

Go to Step 17

--

15

Replace the appropriate fuel injector.

Did you complete the replacement?

--

Go to Step 17

--

16

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

--

Go to Step 17

--

17
  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 18

18

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK