GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Optra 🢒 Engine 🢒 Engine Controls - 1.6L (L91) 🢒 DTC P1476

Circuit Description

Voltage is provided to the exhaust gas recirculation (EGR) solenoid by the ignition 1 voltage circuit through a fuse. Ground is provided to the EGR solenoid on the control circuit by a low side driver within the engine control module (ECM). The ECM energizes the solenoid which allows vacuum to pass to the EGR valve. The ECM monitors the voltage on the control circuit of the EGR valve to determine if a failure is present. If ECM detects the voltage on the control circuit of the EGR solenoid is low while the valve is not commanded while the solenoid is being commanded, this DTC sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1476 Exhaust Gas Recirculation (EGR) Solenoid Control Circuit Short to Voltage

Conditions for Setting the DTC

The ECM detects a short to voltage on the control circuit of the EGR solenoid.

Test Description

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

  1. A click should be heard or felt when the valve operates. Ensure that both the ON and the OFF states are commanded. Repeat the commands as necessary.

    2.

  2. This step verifies that the ECM is providing ground to the EGR solenoid.

Step

Action

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

  1. Turn ON the ignition, with the engine OFF.
  2. With the scan tool, command the EGR solenoid ON and OFF.

Do you hear or feel a click from the EGR solenoid when the valve is commanded ON and OFF?

Go to Step 3

Go to Step 4

3
  1. Observe the Freeze Frame/Failure Records data for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Operate the vehicle within the Conditions for Running the DTC.

Did the DTC fail this ignition?

Go to Step 4

Go to Intermittent Conditions

4

  1. Disconnect the EGR solenoid electrical connector.
  2. Connect a test lamp between the control circuit of the EGR solenoid and the ignition 1 voltage circuit of the EGR solenoid.
  3. With a scan tool, command the EGR solenoid ON and OFF.

Does the test lamp turn ON and OFF with each command?

Go to Step 6

Go to Step 5

5

Test the control circuit of the EGR solenoid for a short to voltage. Refer to Testing for a Short to Voltage and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 7

6

Test for shorted terminals and for a poor connection at the EGR solenoid . 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 10

Go to Step 8

7

Test for shorted terminals 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 10

Go to Step 9

8

Replace the EGR solenoid.

Did you complete the replacement?

Go to Step 10

--

9

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

Go to Step 10

--

10
  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.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 11

11

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK