P0403
SYSTEM DESCRIPTION
This system controls flow rate of EGR led from exhaust manifold to intake manifold. The opening of the EGR bypass passage in the EGR volume control valve changes to control the flow rate. A built-in step motor moves the valve in steps corresponding to the ECM output pulses. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is determined by considering various engine conditions. The EGR volume control valve remains closed under the following conditions.
- Engine stopped
- Engine starting
- Engine idling
- Low engine coolant temperature
- Excessively high engine coolant temperature
- High engine speed
- Wide open throttle
- Low battery voltage
COMPONENT DESCRIPTION
EGR volume control valve
The EGR volume control valve uses a step motor to control the flow rate of EGR from exhaust manifold. This motor has four winding phases. It operates according to the output pulse signal of the ECM. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes, changing the flow rate. When no change in the flow rate is needed, the ECM does not issue the pulse signal. A certain voltage signal is issued so that the valve remains at that particular opening.
Consult-II Reference Value In Data Monitor Mode:
Fail-Safe Mode:
On Board Diagnosis Logic
Malfunction is detected when an improper voltage signal is sent to ECM through the valve.
FAIL-SAFE MODE
When the ECM enters the fail-safe mode, the MIL illuminates.
Possible Cause
- Harness or connectors
(EGR volume control valve circuit is open or shorted.)
- EGR volume control valve
DTC Confirmation Procedure
NOTE: If "DTC Confirmation Procedure" has been previously conducted, always turn ignition switch "OFF" and wait at least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10 V at idle.
WITH CONSULT-II
1. Turn ignition switch "ON" and select "DATA MONITOR" mode with CONSULT-II.
2. Start engine and warm it up to normal operating temperature.
3. Rev engine from idle to 2,000 rpm 10 times.
4. If 1st trip DTC is detected, go to "Diagnostic Procedure" below.
WITH GST
Follow the procedure "With CONSULT-II" above.
EC-EGVC/V-01:
EC-EGVC/V-01 Connector View:
ECM Terminals And Reference Value:
Wiring Diagram
Diagnostic Procedure
Diagnostic Procedure Steps 1 - 2:
Diagnostic Procedure Steps 3 - 4:
