GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2001 🢒 Regal (China) 🢒 DTC 🢒 DTC P0201, P0202, P0203, P0204, P0205, or P0206

Circuit Description

The powertrain control module (PCM) enables the appropriate fuel injector on the intake stroke for each cylinder. A voltage is supplied directly to the fuel injectors. The PCM controls each fuel injector by grounding the control circuit via a solid state device called a driver. The PCM monitors the status of each driver. If the PCM detects an incorrect voltage for the commanded state of the driver, a fuel injector control DTC sets.

Conditions for Running the DTC
    • The engine is running.
    • The ignition voltage is between 9 and 18 volts.

Conditions for Setting the DTC
    • The PCM detects an incorrect voltage on the fuel injector control circuit.
    • The condition exists for 30 seconds.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure.
    • The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using 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 .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. The misfire current counters may not increment if certain DTCs are set. Use a scan tool to clear the DTCs. Monitoring the misfire current counters isolates which fuel injector is not operating. A cylinder that is misfiring can also cause the misfire current counters to increment for another cylinder. Diagnose the cylinder with the highest level of misfire first.

    2.

  2. This step isolates the condition. If the test lamp blinks, the PCM is providing ground to the fuel injector.

    3.

  3. This step tests if a ground is constantly being applied to the fuel injector.

    4.

  4. This step isolates the circuit between the multi-way connector and the PCM. An open or short to voltage on the fuel injector control circuit will not allow the test lamp to blink.

    5.

  5. This step inspects for fuel injector harness damage between the multi-way connector and the upper intake manifold. Careful inspection may isolate the condition before removal of the upper intake manifold.

    6.

  6. Perform the continuity test at the multi-way connector. If the DMM displays OL test the circuits for an open or a poor connection.

  7. This step isolates the circuit between the multi-way connector and the fuel injector. A short to voltage on the fuel injector control circuit will set this DTC.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. With a scan tool clear the DTCs.
  2. Idle the engine at the normal operating temperature.
  3. With a scan tool, monitor the misfire current counters.

Are any of the misfire current counters incrementing?

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, or within the parameters observed in the Freeze Frame/Failure Records.

Does the DTC fail this ignition?

Go to Step 4

Go to Diagnostic Aids

4

  1. Turn OFF the ignition.
  2. Disconnect the fuel injector harness multi-way connector.
  3. Probe the appropriate fuel injector control circuit, PCM side, with a test lamp connected to B+.
  4. Crank the engine.

Does the test lamp blink when cranking the engine?

Go to Step 8

Go to Step 5

5

Does the test lamp remain illuminated at all times?

Go to Step 7

Go to Step 6

6

Test the control circuit of the fuel injector for a short to voltage or an open between the multi-way connector and the PCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 14

7

Test the control circuit of the fuel injector for a short to ground between the multi-way connector and the PCM. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 17

8

Inspect the accessible fuel injector jumper harness between the multi-way connector and the plenum for the following:

    • Poor connections at the multi-way connector
    • Damaged or pinched wiring
    • Broken wires inside the insulation

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 18

Go to Step 9

9
  1. Remove the upper intake. Refer to Upper Intake Manifold Replacement in Engine Mechanical - 2.5L (LB8) and 3.0L (LW9).
  2. Probe the appropriate fuel injector control circuit, fuel injector side, at the multi-way connector, with a test lamp connected to B+.

Does the test lamp illuminate?

Go to Step 15

Go to Step 10

10

With a DMM, test for continuity between the ignition voltage terminal and the appropriate fuel injector control circuit terminal, at the multi-way connector. Refer to Testing for Continuity .

Does the DMM indicate OL?

Go to Step 11

Go to Step 13

11

Test the control circuit of the fuel injector for an open, or poor connections 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 18

Go to Step 12

12

Test the ignition voltage circuit of the fuel injector for an open between the fuel injector and the splice. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 16

13

Test the control circuit of the fuel injector for a short to voltage, or a short to another circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 16

14

Inspect for poor connections at the harness connector of the PCM. 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 18

Go to Step 17

15

Repair the short to ground in the fuel injector control circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 18

--

16

Replace the appropriate fuel injector. Refer to Fuel Injector Replacement .

Did you complete the replacement?

Go to Step 18

--

17

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

Go to Step 18

--

18
  1. Use the scan tool in order to clear the DTCs.
  2. Turn OFF the ignition for 30 seconds.
  3. Operate the vehicle within the Conditions for Running the DTC.

Does the DTC run and pass?

Go to Step 19

Go to Step 2

19

With a scan tool, observe the stored information in Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK