GM Service Manual Online
For 1990-2009 cars only

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 an incorrect voltage for the commanded state of the driver, DTC P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208 sets.

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
    • DTC P0205 Injector 5 Control Circuit
    • DTC P0206 Injector 6 Control Circuit
    • DTC P0207 Injector 7 Control Circuit
    • DTC P0208 Injector 8 Control Circuit

Conditions for Running the DTC

    • The engine speed is more than 40 RPM.
    • The system voltage is between 8-18 volts.
    • DTCs P0201-P0208 run continuously once the above conditions have been met.

Conditions for Setting the DTC

    • The ECM detects an open 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

    • The odd coils fuse and the even coils fuse supply power to the fuel injectors. Refer to Engine Controls Schematics .
    • 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.

Is DTC P0201, P0202, P0203, P0204, P0205, P0206, P0207, or P0208 set?

Go to Step 3

Go to Step 5

3

Are DTCs P0201, P0203, P0205, and P0207 set at the same time?

Go to Step 11

Go to Step 5

4

Are DTCs P0202, P0204, P0206, and P0208 set at the same time?

Go to Step 12

Go to Step 5

5

  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 6

Go to Diagnostic Aids

6

  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 battery voltage. Refer to Probing Electrical Connectors in Wiring Systems.
  5. Crank the engine.

Does the test lamp flash while cranking the engine?

Go to Step 8

Go to Step 7

7

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

Did you find and correct the condition?

Go to Step 16

Go to Step 9

8

  1. Turn ON the ignition, with the engine OFF.
  2. Probe the ignition 1 voltage circuit 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 9

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 16

Go to Step 14

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 16

Go to Step 15

11

Repair the short to ground in the ignition 1 voltage circuit of the odd fuel injectors.

Did you complete the repair?

Go to Step 16

--

12

Repair the short to ground in the ignition 1 voltage circuit of the even fuel injectors.

Did you complete the repair?

Go to Step 16

--

13

Repair the open in the ignition 1 voltage circuit of the fuel injector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 16

--

14

Replace the affected fuel injector. Refer to Fuel Injector and Fuel Rail Replacement .

Did you complete the replacement?

Go to Step 16

--

15

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 16

--

16

  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 17

17

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