Note. In the event of a malfunction that causes the exhaust gas recirculation system to operate continuously (HORN), black or white smoke may come out of the engine exhaust pipe.
Checking if the EGR valve is installed correctly
Start the engine and check that it starts easily and runs smoothly at idle.
Checking the condition of a warm engine (with portable diagnostic tool II)
Warm up the engine.
Turn off the ignition (OFF).
Connect the Handheld Diagnostic Tool II to the DLC3 connector.
Start the engine at idle.
Turn on the portable diagnostic tool II.
To confirm the data specified in the DATA LIST, select the instrument mode: «Powertrain/ Engine and ECT/ Active Test/ EGR Step»
Let the engine warm up. The coolant temperature must be between 75–90°C.
Check the air flow at idle speed of the engine.
Verification conditions: the measured value of the air flow must be in the range of 4–16 g/s.
Use the handheld diagnostic tool to change EGR valve modes. Set the valve opening degree to 0 and check the air flow rate on the instrument.
Verification conditions: the measured value of the air flow must be in the range of 10–16 g/s.
If the measured air flow is not correct, the EGR valve must be replaced.
If the measured value of the air flow does not correspond to the set value, the flow meter should be checked.
In case of its serviceability, the operation of the EGR valve should be checked.
If the flow meter is faulty, replace it, then check the operation of the EGR valve.
Checking the condition of a warm engine (without using a portable diagnostic tool II)
Using a tee, connect a vacuum gauge to the hose between the intake manifold and the boost pressure sensor.
Start the engine and let it warm up. The coolant temperature must be between 75–90°C.
The vacuum gauge should show a vacuum of at least 2.5 kPa.
Stop the engine by switching off the ignition and disconnect the EGR valve connector.
Start the engine again at idle speed. In this case, the vacuum gauge should show a vacuum of no more than 2.5 kPa.
If the vacuum exceeds this value, the EGR valve must be replaced.
EGR Valve Check
Pic. 2.601. Valve connector pins
Using an ohmmeter, measure the resistance between the contacts of the valve connector (pic. 2.601).
If the resistance between the contacts of the valve connector does not correspond to the permissible values indicated in the table, then the valve must be replaced.