Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Manifold Pressure/Vacuum Sensor: Testing and Inspection

- Disconnect MAP sensor vacuum hose from filter.
- Disconnect coupler from MAP sensor.
- Remove MAP sensor.





- Arrange 3 new 1.5V batteries in series (check that total voltage is 4.5-5.0V) and connect its positive terminal to "VIN" terminal of sensor and negative terminal to "Ground" terminal. Then check voltage between "Vout" and "Ground". Also, check if voltage reduces when vacuum is applied up to 4OcmHg by using vacuum pump.

Output voltage (V in voltage 4.5 - 5.0V, ambient temp. 2O - 3O°C, 68 - 86°F)





If check result is not satisfactory, replace MAP sensor.
- Install MAP sensor and connect vacuum hose securely.
- Connect MAP sensor coupler securely.