Test Description

The number below refers to the step number on the diagnostic table.

6: This step tests for voltage that is constantly being applied to the EGR valve.

DTC P0403

Step	Action	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2	Turn ON the ignition, with the engine OFF. Command the EGR from 0 percent to 100 percent with a scan tool. Does the EGR Position Sensor parameter remain within 3 percent of the desired EGR Position parameter when commanded with a scan tool?	Go to Step 3	Go to Step 4
3	Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?	Go to Step 4	Go to Intermittent Conditions
4	Turn OFF the ignition. Disconnect the exhaust gas recirculation (EGR) valve. Turn ON the ignition, with the engine OFF. Probe the EGR solenoid high control circuit with a test lamp that is connected to a good ground. Command the EGR valve from 0-10 percent and from 10-0 percent with a scan tool. Does the test lamp turn ON at 10 percent and OFF at 0 percent when commanded with a scan tool?	Go to Step 5	Go to Step 6
5	Connect a test lamp between the EGR solenoid high control circuit and the EGR solenoid low control circuit. Command the EGR valve from 0-10 percent with a scan tool. Does the test lamp illuminate?	Go to Step 10	Go to Step 9
6	Does the test lamp remain illuminated when the EGR valve is commanded to 0 percent with a scan tool?	Go to Step 8	Go to Step 7
7	Test the EGR solenoid high control circuit for a short to ground or for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 11
8	Test the EGR solenoid high control circuit 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 14	Go to Step 11
9	Test the EGR solenoid low control circuit for an open or for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 14	Go to Step 11
10	Test for an intermittent and for a poor connection at the EGR valve. 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 14	Go to Step 12
11	Test for an intermittent and for a poor connection at the powertrain control module (PCM). 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 14	Go to Step 13
12	Replace the EGR valve. Refer to Exhaust Gas Recirculation (EGR) Valve Replacement . Did you complete the replacement?	Go to Step 14	-
13	Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?	Go to Step 14	-
14	Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?	Go to Step 2	Go to Step 15
15	Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?	Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information	System OK