GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2003 🢒 Regal 🢒 Engine 🢒 Engine Electrical 🢒 Fuel Injector Circuit Diagnosis

Circuit Description

The control module enables the appropriate fuel injector on the intake stroke for each cylinder. An ignition 1 voltage is supplied directly to the fuel injectors. The control module controls each fuel injector by grounding the control circuit via a solid state device called a driver.

Diagnostic Aids
    • Monitoring the fuel injector circuit status with a scan tool, while moving the fuel injector harness, may help to isolate an intermittent condition.
    • 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 .

Test Description

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

  1. This step tests for a short to ground on the ignition 1 voltage supply circuit of the fuel injector.

    2.

  2. This step tests for an open ignition 1 voltage supply circuit between the injector fuse and a fuel injector electrical connector.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module 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

Are any fuel injector DTCs set?

Go to DTC P0201, P0202, P0203, P0204, P0205, or P0206

Go to Step 3

3

Inspect the fuel injector fuse.

Is the fuel injector fuse open?

Go to Step 4

Go to Step 5

4
  1. Turn OFF the ignition.
  2. Disconnect an electrical connector of a fuel injector.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 1 voltage supply circuit of a fuel injector with a test lamp connected to B+.

Does the test lamp illuminate?

Go to Step 6

Go to Diagnostic Aids

5
  1. Turn OFF the ignition.
  2. Disconnect an electrical connector of a fuel injector.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 1 voltage supply circuit of the fuel injector with a test lamp connected to a good ground.

Does the test lamp illuminate?

Go to DTC P0341

Go to Step 7

6
  1. Test the ignition 1 voltage supply circuit of each fuel injector for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
  2. Replace the fuse.

Did you complete the action?

Go to Step 8

--

7

Repair the open or poor connection in the ignition 1 voltage supply circuit of the fuel injectors. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 8

--

8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3