GM Service Manual Online
For 1990-2009 cars only

Circuit Description

Voltage is provided to the exhaust gas recirculation (EGR) valve by the ignition 1 voltage circuit through a fuse. Ground is provided to the EGR valve on the control circuit by a low side driver within the engine control module (ECM). 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 valve is low while the valve is not commanded or high while the valve is being commanded, DTC P1403 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1403 Exhaust Gas Recirculation (EGR) Solenoid Control Circuit

Conditions for Running the DTC

    • DTCs P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0131, P0300, P0335, P0336, P0341, and P0342 are not set.
    • The engine speed is between 1,950-2,600 RPM.
    • The ignition 1 voltage is more 10 volts.
    • The engine controls system is in Closed Loop.
    • The engine coolant temperature (ECT) is greater than 60°C (140°F).
    • The intake air temperature (IAT) is greater than 15°C (59°F).
    • The manifold absolute pressure (MAP) is greater than 75 kPa (11 psi).
    • The mass airflow (MAF) is between 71-174 mg/tdc.
    • DTC P1403 runs continuously once the above conditions are met.

Conditions for Setting the DTC

The ECM detects the voltage on the control circuit of the EGR valve is low while the valve is not commanded or high while the valve is being commanded.

Actions Taken When the DTC Sets

    • The malfunction indicator lamp (MIL) will illuminate after 3 consecutive trips with a fail.
    • The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.

Conditions for Clearing the MIL/DTC

    • The MIL will turn OFF after 4 consecutive ignition cycles in which the diagnostic runs without a fault.
    • DTCs can be cleared by using the scan tool.
    • Disconnect the ECM battery feed for more than 10 seconds.

Test Description

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

  1. This step tests for an open in the ignition 1 voltage circuit of the EGR valve.

  2. This step tests for a short to ground in the control circuit of the EGR valve.

  3. This step tests for an open in the control circuit of the EGR valve.

  4. This step tests for high resistance in the control circuit of the EGR valve.

  5. This step tests for a high resistance in the 5-volt reference or low reference circuit of the EGR valve.

  6. This step tests for a high resistance in the signal circuit of the EGR valve.

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 P0405 or P0406 also set?

 

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

  1. Turn ON the ignition, with the engine OFF.
  2. Observe the EGR Position Sensor parameter with a scan tool.

Is the voltage within the specified range?

0.60-0.8 V

Go to Step 4

Go to Step 11

4

  1. Command the EGR valve from 0 percent to 100 percent with a scan tool.
  2. Observe the EGR Position Sensor parameter with a scan tool.

Is the voltage more than the specified value?

3.70 V

Go to Step 5

Go to Step 6

5

  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 6

Go to Intermittent Conditions

6

  1. Turn OFF the ignition.
  2. Disconnect the exhaust gas recirculation (EGR) valve.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between the ignition 1 voltage circuit of the EGR valve and a good ground.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 20

7

Connect a test lamp from the ignition 1 voltage circuit to the control circuit of the EGR valve.

Does the test lamp illuminate?

--

Go to Step 14

Go to Step 8

8

  1. Connect a test lamp from the ignition 1 voltage circuit to the control circuit of the EGR valve.
  2. Command the EGR valve to 100 percent.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 14

9

  1. Turn OFF the ignition.
  2. Disconnect the fuse that supplies ignition 1 voltage to the EGR valve.
  3. Measure the resistance of the ignition 1 voltage circuit of the EGR valve from the fuse terminal to the harness connector terminal of the EGR valve.

Is the resistance less than the specified value?

3 ohms

Go to Step 10

Go to Step 20

10

  1. Turn ON the ignition, with the engine OFF.
  2. Probe the control circuit of the EGR valve with a test lamp connected to battery positive voltage.
  3. Command the EGR valve to 100 percent.
  4. Measure the voltage from the probe of the test lamp to a good ground.

Is the voltage less than the specified value?

0.3 V

Go to Step 18

Go to Step 14

11

  1. Turn OFF the ignition.
  2. Disconnect the EGR valve.
  3. Turn ON the ignition, with the engine OFF.
  4. Important: Use a test lamp that measures between 25-30 ohms.

  5. Connect a test lamp between the 5-volt reference circuit and the low reference circuit of the EGR valve position sensor.

Does the test lamp illuminate?

--

Go to Step 13

Go to Step 12

12

Connect a test lamp between the 5-volt reference circuit of the EGR valve position sensor and a good ground.

Does the test lamp illuminate?

--

Go to Step 16

Go to Step 15

13

  1. Connect a 3-amp fused jumper wire between the signal circuit and the low reference circuit of the EGR valve position sensor.
  2. Observe the EGR Position Sensor parameter on the scan tool.

Is the parameter less than the specified value?

0.05 V

Go to Step 18

Go to Step 17

14

Test the control circuit of the EGR valve for one of the following conditions:

    • An open
    • A short to ground
    • A short to voltage
    • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 19

15

Test the 5-volt reference circuit of the EGR valve position sensor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 19

16

Test the low reference circuit of the EGR valve position sensor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 19

17

Test the signal circuit of the EGR valve position sensor for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 19

18

Test the EGR valve for the following:

    • Excessive deposits on the EGR valve pintle that may interfere with the EGR valve pintle extending completely or cause the pintle to stick.
    • An intermittent and poor connection at the EGR valve. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 21

19

Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 23

Go to Step 22

20

Repair the ignition 1 voltage circuit of the EGR valve for one of the following conditions:

    • An open
    • A short to ground
    • High resistance

Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 23

--

21

Replace the EGR valve.

Did you complete the replacement?

--

Go to Step 23

--

22

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

--

Go to Step 23

--

23

  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 24

24

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List

System OK