P0403

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) controls the movement of the valve using the Exhaust Gas Recirculation (EGR) control circuit. The control circuit consists of a high side driver and feed circuit, the EGR solenoid, and a ground circuit. The PCM turns ON the high side driver to supply ignition voltage to the EGR control circuit. The PCM monitors the high side driver for improper voltage levels in the EGR control circuit. If the PCM detects an improper voltage in the EGR control circuit, DTC P0403 will set.

CONDITIONS FOR RUNNING THE DTC
^ The engine speed is more than 425 RPM.
^ System voltage is between 9-18 volts.

CONDITIONS FOR SETTING THE DTC
The PCM detects an improper voltage in the EGR ignition feed, EGR solenoid, or EGR ground circuit for at least 10 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails.
^ The PCM stores the conditions present when the DTC set as Freeze Frame and Fail Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes.
^ The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using the scan tool Clear DTC Information function.

DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions. Initial Inspection and Diagnostic Overview

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the EGR valve can be commanded open.
3. Excessive resistance in the EGR control circuit or the EGR ground circuit will result in the EGR not responding correctly to the commanded EGR position.
4. This step tests the EGR Valve control circuit.
5. This step tests the EGR Valve ground circuit.
6. Excessive resistance in the control circuit or the ground circuit will cause this DTC to set. With the EGR commanded to 100 percent the test lamp should light with full intensity. Connect the test lamp across the battery terminals and compare the test lamp intensity to the EGR control circuit intensity.