Exhaust Gas Recirculation: Testing and Inspection

PROCEDURE

1. CHECK AND CLEAN FILTER IN EXHAUST GAS RECIRCULATION (EGR) VACUUM MODULATOR.



- Remove the cap and filter.
- Check the filter for contamination or damage.
- Using compressed air, clean the filter.
- Reinstall the filter and cap.
- Install the filter with the coarser surface facing out to the atmospheric side.

2. INSTALL VACUUM GAUGE.



- Using a 3-way connector, connect a vacuum gauge to the hose between the EGR Valve and the Vacuum Switching Valve (VSV).

3. INSPECT SEATING OF EGR VALVE.
- Check that the engine starts and runs at idle.

4. CONNECT TE1 AND E1 OF DLC 1.



- Using a jumper wire or SST, connect terminal TE1 and E1 of the Data Link Connector (DLC) 1. (SST 09843-18020).

5. INSPECT VSV OPERATION WITH COLD ENGINE.
- The engine coolant temperature should be below 60°C (140°F) for automatic transmission and 55°C (131°F) for manual transmission.



- Check that the vacuum gauge indicates zero at 2,500 rpm.

6. INSPECT OPERATION OF VSV AND EGR VACUUM MODULATOR WITH HOT ENGINE.
- Warm engine up to operating temperature.



- Check that the vacuum gauge indicates low vacuum at 2,500 rpm.
- Disconnect the vacuum hose from port R of the EGR Vacuum Modulator and connect port R directly to the intake manifold with another hose.



- Check that the vacuum gauge indicates high vacuum at 2.500 rpm.

NOTE: As exhaust gas is increasingly recirculated, the engine will start to misfire.

- Remove vacuum gauge and reconnect the vacuum hoses to their proper locations.

7. INSPECT EGR VALVE.



- Apply vacuum directly to the EGR valve with the engine at idle.
- Check that the engine runs rough or dies.
- Reconnect the vacuum hoses to their proper locations.
- Remove the jumper wire from the DLC 1.

^ IF NO PROBLEM IS FOUND DURING THIS INSPECTION, SYSTEM IS NORMAL; OTHERWISE INSPECT INDIVIDUAL COMPONENTS.

NOTE: For more information on EGR system testing refer to "DTC 71" under "Diagnostic Charts" /" Trouble Code Charts".
Testing and Inspection