GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The control module enables the appropriate fuel injector pulse for each cylinder. Ignition voltage is supplied 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 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 .

Step

Action

Values

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

Is DTC P0200 set?

--

Go to DTC P0200

Go to Step 3

3

Inspect the ECM 1 fuse.

Is the ECM 1 fuse open?

--

Go to Step 4

Go to Step 6

4

  1. Turn OFF the ignition.
  2. Disconnect the multi-way harness connector of the fuel injectors.
  3. Probe the ignition 1 voltage circuit of a fuel injector, fuse side, with a test lamp that is connected to battery voltage. Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 5

5

Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

--

Go to Step 11

Go to Diagnostic Aids

6

  1. Turn OFF the ignition.
  2. Disconnect the multi-way harness connector of the fuel injectors.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 1 voltage circuit of the fuel injector, fuse side, 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 7

Go to Step 9

7

Measure the resistance from the ECM 1 fuse to the ignition 1 voltage circuit terminal of a fuel injector with a DMM. Refer to Circuit Testing in Wiring Systems.

Is the resistance more than the specified value?

5ohms

Go to Step 10

Go to Intermittent Conditions

8

Test the ignition 1 voltage circuit of the fuel injectors 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 12

--

9

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

Did you complete the repair?

--

Go to Step 12

--

10

Repair the high resistance in the ignition 1 voltage circuit of the fuel injectors. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 12

--

11

Repair the short to a PCM ground in the ignition 1 voltage circuit of the fuel injectors. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 12

--

12

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3