Note. Before performing any diagnostic test, refer toWARNINGS, CAUTIONS and NOTES in DIAGNOSTIC TESTS .
Note. Testing individual components does not isolate shorts or opens. Perform all voltage tests using a Digital Volt-Ohmmeter Meter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use ohmmeter to isolate wiring harness shorts or opens.
Diagnostic Aids
Exhaust gas flow signal changes little when Exhaust Gas Recirculation (EGR) valve solenoid is turned on. Manifold Absolute Pressure (MAP) sensor signal is used for detection. Check for following possible problems
- Blocked and/or leakage vacuum hose between EGR control valve and intake manifold vacuum port.
- Blocked and/or leakage vacuum hose between EGR solenoid valve and intake manifold vacuum port.
- Misplaced, loose or corroded connectors terminals at MAP sensor and EGR solenoid valve.
- Leakage in EGR control valve.
- Poor connection at EGR system vacuum hoses.
- Stuck close EGR control valve.
- Stuck open EGR control valve.