GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Optra 🢒 Engine 🢒 Engine Controls - 1.8L (L79) 🢒 DTC P0201, P0202, P0203, or P0204

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 an incorrect voltage for the commanded state of the driver, a diagnostic trouble code (DTC) will set.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC P0201 Injector 1 Control Circuit
    • DTC P0202 Injector 2 Control Circuit
    • DTC P0203 Injector 3 Control Circuit
    • DTC P0204 Injector 4 Control Circuit

Conditions for Running the DTC
    • The engine speed is more than 700 RPM.
    • The ignition 1 voltage is more than 9 volts.
    • The DTCs P0201-P0204 run continuously once the above conditions are met.

Conditions for Setting the DTC
    • The control module detects an incorrect voltage on the fuel injector control circuit.
    • The above condition is met for 5 seconds.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 4 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 .
    • For an intermittent condition, refer to Intermittent Conditions .

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connect End View Reference: 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 diagnostic trouble code (DTC) with a scan tool.
  3. Start the engine.
  4. Observe the DTC Info with a scan tool.

Does DTC P0201, P0202, P0203, or P0204 set?

Go to Step 4

Go to Step 3

3
  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 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 the J 34730-405 Injector 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 9

Go to Step 6

6

Does the test lamp remain illuminated at all times?

Go to Step 8

Go to Step 7

7

Test the control circuit of the fuel injector for an open and 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 14

Go to Step 10

8

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 14

Go to Step 13

9

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 14

Go to Step 12

10

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 14

Go to Step 13

11
  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 14

--

12

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

Did you complete the replacement?

Go to Step 14

--

13

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

Go to Step 14

--

14
  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 15

15

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