GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Aveo 🢒 Engine 🢒 Engine Controls - 1.6L (L91) 🢒 Fuel Injector Circuit Diagnosis

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.

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

Values

Yes

No

Schematic Reference: Engine Controls Schematics

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

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

--

Go to DTC P0201, P0202, P0203, or P0204

Go to Step 3

3
  1. Turn OFF the ignition.
  2. Disconnect the fuel injectors.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 1 voltage circuit of a 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 4

Go to Step 11

4
  1. Remove the fuse for the fuel injector ignition 1 voltage circuit.
  2. Measure the resistance from the 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?

3 ohms

Go to Step 12

Go to Step 5

5
  1. Install the fuse for the fuel injector ignition 1 voltage circuit.
  2. Connect the J 34730-405 Injector Test Lamp into each injector connector one at a time.
  3. Crank the engine.

Does the test lamp flash brightly for each injector?

--

Go to Intermittent Conditions

Go to Step 6

6

Does the test lamp remain illuminated at all times for any injector circuit?

--

Go to Step 8

Go to Step 7

7

Test the control circuit of the affected 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 15

Go to Step 9

8

Test the control circuit of the affected 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 15

Go to Step 14

9
  1. Disconnect the engine control module (ECM).
  2. Measure the resistance on the affected fuel injector control circuit with a DMM. Refer to Circuit Testing in Wiring Systems.

Is the resistance more than the specified value?

15 ohms

Go to Step 13

Go to Step 10

10

Test for an intermittent and for a poor connection at the 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 15

Go to Step 14

11

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 15

--

12

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 15

--

13

Repair the high resistance in the control circuit of the fuel injector. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

14

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

--

Go to Step 15

--

15

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2