Exhaust Gas RECIRCULATION (EGR) System Test: Turbo
- Remove cap and filters from top of EGR vacuum modulator. Ensure filters are clean and in good condition. Clean filters with compressed air (if necessary).NOTE: Filters must be installed in EGR vacuum modulator with coarse side facing upward, away from EGR vacuum modulator.
- Reinstall filters and cap. Using 3-way connector, install vacuum gauge in vacuum hose between top of EGR valve and EGR vacuum modulator. Start engine. Ensure engine runs idles smoothly to ensure proper seating of EGR valve.
- To check operation of EGR Vacuum Switching Valve (VSV) with engine cold, ensure engine coolant temperature is less than 122°F (50°C) on A/T models or 149°F (65°C) on M/T models. Block all 4 wheels. Apply parking brake. Start engine and allow engine to idle. Apply service brakes.
- On A/T models, place transmission in Drive. Increase and maintain engine speed at 1600-1800 RPM. Ensure no vacuum reading is obtained on vacuum gauge with engine at 1600-1800 RPM. Proceed to step 6).
- On M/T models, place transmission in Neutral. Increase and maintain engine speed at 3500-4000 RPM. Ensure no vacuum reading is obtained on vacuum gauge with engine at 3500-4000 RPM. Go to next step.
- To check operation of EGR VSV with engine warm, operate engine until engine coolant temperature is greater than 122°F (50°C) on A/T models or 149°F (65°C) on M/T models. Ensure parking brake and service brakes are applied.
- On A/T models, place transmission in Drive. Increase and maintain engine speed at 1600-1800 RPM. Ensure low vacuum is now obtained with engine at 1600-1800 RPM. Go to step 9).
- On M/T models, place transmission in Neutral. Increase and maintain engine speed at 3500-4000 RPM. Ensure low vacuum is momentarily obtained with engine at 3500-4000 RPM. Go to next step.
- Allow engine to idle. To check EGR valve operation, remove vacuum gauge and plug vacuum hose at top of EGR valve.
- Using vacuum pump, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall if EGR valve is operating properly. If EGR system does not operate as described, each individual component should be tested. Reconnect vacuum hose at EGR valve.