DTC 0514

SYSTEM DESCRIPTION
This system outs and controls vacuum applied to the EGR valve to suit engine operating conditions. This cut-and-control operation is accomplished through the ECM and the EGRC-solenoid valve. When the ECM detects any of the following conditions, current flows through the solenoid valve. This causes the port vacuum to be discharged into the atmosphere. The EGR valve remains closed.
- Low engine coolant temperature
- Engine starting
- High-speed engine operation
- Engine idling
- Excessively high engine coolant temperature
- Mass air flow sensor malfunction


COMPONENT DESCRIPTION






Exhaust gas recirculation (EGR) valve
The EGR valve controls the amount of exhaust gas routed to the intake manifold. Vacuum is applied to the EGR valve in response to throttle valve opening. The vacuum controls the movement of a taper valve connected to the vacuum diaphragm in the EGR valve.






EGRC-solenoid valve
The EGRC-solenoid valve responds to signals from the ECM. When the ECM sends an ON (ground) signal, the coil in the solenoid valve is energized. A plunger will then move to flow the vacuum signal (from the intake manifold collector to the EGR valve). The vacuum signal passes through the solenoid valve. The signal then reaches the EGR valve.
When the ECM sends an OFF signal, the plunger is returned by the spring which cuts the vacuum signal.









ON BOARD DIAGNOSIS LOGIC
If EGR temperature sensor detects EGR flow under the condition that does not call for EGR, a high-flow malfunction is diagnosed.









DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

NOTE: If "DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.

TESTING CONDITION:
Always perform the test at a temperature of -10°C (14°F) or higher.
Engine coolant temperature and EGR temperature must be verified in "DATA MONITOR" mode with CONSULT before starting DTC WORK SUPPORT test. If it is out of range below, the test cannot be conducted.

COOLAN TEMP/S: -10 to 40°C (14 to 104°F)
EGR TEMP SEN: Less than 4.8V

If the values are out of the ranges indicated above, park the vehicle in a cool place and allow the engine temperature to stabilize. Do not attempt to reduce the coolant or EGR temperature with a fan or means other than ambient air. Doing so may produce an inaccurate diagnostic result.







Without Scan Tools
1) Turn ignition switch "ON".
2) Check the following voltages.

ECM terminal (59) (engine coolant temperature) and ground:
1.5 - 4.4V

ECM terminal (63) (EGR temperature) and ground:
Less than 4.8V

3) Start engine and let it idle for at least 70 seconds.
4) Turn ignition switch "OFF", wait at least 5 seconds and then turn "ON".
5) Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.







Electrical Diagrams






Circuit Connectors

1 Of 3:

DIAGNOSTIC PROCEDURE


COMPONENT INSPECTION






EGR valve
Apply vacuum to EGR vacuum port with a hand vacuum pump. EGR valve spring should lift.
Check for sticking.
If NG, repair or replace EGR valve.









EGRC-solenoid valve
Check solenoid valve, following the table as shown below:
If NG, replace EGRC-solenoid valve.












EGR temperature sensor
Check resistance change and resistance value.
If NG, replace EGR temperature sensor.






EGRC-BPT valve
1. Plug one of two ports of EGRC-BPT valve.
2. Vacuum from the other port and check for leakage while applying a pressure above 0.981 kPa (100 mmH2O, 3.94 inH2O) from under EGRC-BPT valve.
3. If a leakage is noted, replace the valve.