EGR Control Solenoid: Testing and Inspection

5M-GE, 1986-88 7M-GE & 7M-GTE Engines

1. Connect terminals of vacuum switching valve to battery voltage.
2. Blow air into either pipe and ensure air flows from other pipe.
3. Disconnect battery voltage.
4. Blow air into either pipe and ensure air does not flow from other pipe.
5. If air flow is not as described, replace valve.
6. Using ohmmeter, check continuity between terminals and valve body.
7. If there is continuity, replace valve.
8. Using ohmmeter, measure resistance between terminals.
9. If resistance is not 38 to 44 ohms at 68°F, replace valve.

Fig. 34 Vacuum switching valve test connections.:

4A-GE, 4A-GEC, 4A-GEL & 4A-GELC Engines

1. Apply battery voltage to vacuum switching valve terminals, Fig. 34.
2. Blow air into pipe ``E,'' Fig. 34, and ensure air flows from pipe ``F.''
3. Disconnect voltage from valve, then blow air into pipe ``E,'' and ensure air flows from air filter at bottom of valve.
4. If air flow is not as described, replace valve.
5. Check for continuity between terminals and valve body and replace valve if continuity exists.
6. Measure resistance between valve terminals and replace valve if resistance does not measure 33-39 ohms at 68°F.