DTC Confirmation Test (Overall Function Check)

NOTE: Use the following test to check overall function of EGRC-BPT. During this test, DTC may not be confirmed.

Malfunction is detected when EGRC-BPT does not operate properly. Possible causes are:

Defective EGRC-BPT.
Defective EGR valve.
Backpressure hose blockage or leak.
Defective Camshaft Position (CMP) sensor.
Plugged exhaust.
Missing orifice in hose between EGRC-BPT and EGRC solenoid.
Defective Mass Airflow (MAF) sensor.
Defective EGRC solenoid.

To check overall function of EGRC-BPT, Install vacuum gauge with a "T" to hose between EGRC-BPT and EGR valve. Raise drive wheels and support vehicle. Disconnect EGRC solenoid hose from EGRC-BPT. Connect a vacuum hose with a .020" (.5 mm) orifice between intake manifold collector and EGRC-BPT (so intake manifold vacuum is directly supplied to EGRC-BPT). Start engine and shift transmission into 1st gear. Observe vacuum gauge while keeping engine speed at 2000-2800 RPM. Vacuum should be 0-5.91 in. Hg. If vacuum is not as specified, go to PROCEDURE . If vacuum is as specified, check EGR system vacuum hoses for blockages or leaks.