Circuit/System Verification
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
- Disconnect the vacuum source from the EGR Cooler Bypass valve.
- Connect the EN-23738-A Mityvac to the Q47 Exhaust Gas Recirculation Cooler Bypass Solenoid Valve vacuum supply hose.
- Engine running, verify the vacuum is greater than -50 kPa (-7. 25 PSI).
- If less than -50 kPa (-7. 25 PSI)
- Ignition OFF.
- Inspect the vacuum supply hose and filter for a leak or restriction
- If the vacuum supply hose and filter are damaged, repair as necessary.
- If the vacuum supply hose and filter are not damaged, replace the vacuum pump.
- Go to next step: If greater than -50 kPa (-7. 25 PSI)
- Connect the vacuum source to the Q47 Exhaust Gas Recirculation Cooler Bypass Solenoid Valve. Engine running, command the EGR Cooler Bypass valve OFF with a scan tool.
- Connect the EN-23738-A Mityvac to the EGR Cooler Bypass valve vacuum port on the EGR Cooler Bypass valve.
- Verify the vacuum is at 0 kPa (0 PSI).
- If greater than 0 kPa (0 PSI)
Replace the Q47 Exhaust Gas Recirculation Cooler Bypass Solenoid Valve.
- Go to next step: If 0 kPa (0 PSI)
- If greater than 0 kPa (0 PSI)
- Command the EGR Cooler Bypass valve ON with a scan tool.
- Verify the vacuum is greater than -50 kPa (-7. 25 PSI).
- If less than -50 kPa (-7. 25 PSI)
Refer to Circuit/System Testing.
- Go to next step: If greater than -50 kPa (-7. 25 PSI)
- If less than -50 kPa (-7. 25 PSI)
- All OK.