Catalytic converter and emission control system (Peugeot Eurovans 806)

All versions of the Bosch Motronic MP3.2 fuel injection system are equipped with a catalytic converter and have a closed-loop system, thanks to which harmful exhaust emissions can be minimized. Closed loop systems are equipped with an oxygen sensor that monitors the oxygen content in the exhaust gases. Low exhaust oxygen levels indicate a rich mixture, while high exhaust oxygen levels indicate a lean mixture.

Carbon Filter Solenoid Valve (CFSV)

Carbon Filter Solenoid Valve (CFSV) (see illustration 11.43) and a carbon canister are used by vehicles equipped with a catalytic converter to reduce fuel vapor emissions into the atmosphere. The charcoal canister stores and absorbs fuel vapors until, under certain operating conditions, the Bosch Motronic electronic control unit opens the charcoal canister solenoid valve (CFSV). Once the electronic control unit activates the CFSV, fuel vapors enter the engine through the throttle valve for complete combustion.





When the ignition is off, the solenoid valve of the carbon filter is open. As soon as the ignition is turned on, the solenoid valve of the carbon filter closes.

With the engine running, the solenoid valve will switch (turn on and off) by the electronic control unit at intervals determined by the control unit. When the engine is turned off and the ignition is turned off, the electronic control unit will close the carbon canister solenoid valve for a few seconds to prevent the engine from starting accidentally.

Values of voltage of the solenoid valve of the carbon filter

Terminal numbers

See illustrations 11.2, 11.3, 11.4, 11.5, 11.6

The resistance value of the carbon filter solenoid valve

Terminal numbers

Influence of external factors

• Damaged or leaking vacuum hoses and joints

Checking the Carbon Filter Solenoid Valve (CFSV) (general check)

1. Inspect the carbon canister solenoid valve multi-pin connector for signs of corrosion or damage.

2. Make sure the connector terminal pins are properly installed and have good contact with the carbon canister solenoid valve multi-pin connector.

Checking the performance of the carbon filter solenoid valve (CFSV)

1. The carbon canister solenoid valve can be controlled via the self-diagnosis (SD) serial port. Please familiarize yourself with the self-diagnosis function and error codes.

2. If the carbon canister solenoid valve does not operate, perform the following checks.

3. Turn on the ignition, check for battery voltage at the power terminal of the carbon filter solenoid valve.

4. If there is no voltage, trace the wiring back to the main fuel injection relay.

5. Check the resistance of the carbon filter solenoid valve.

6. Disconnect the multi-contact connector of the electronic control unit and use a jumper wire to connect the switching terminal in the multi-contact connector of the electronic control unit to ground for a very short time.

7. If the carbon filter solenoid valve is activated, check the main power and ground contacts of the electronic control unit. If the tests do not reveal any faults, then the electronic control unit may be faulty.

8. If the solenoid valve of the carbon filter does not operate, check the continuity of the wiring between the solenoid valve of the carbon filter and the switching terminal of the electronic control unit.



9. If the wiring is OK, then the carbon filter solenoid valve may be faulty.

Carbon Filter Solenoid Valve (CFSV) resistance

• Disconnect the multi-pin connector and measure the resistance of the carbon canister solenoid valve between the two terminals.