Induction Changeover Valve (ICOV) (non-turbocharged models only) (Peugeot Eurovans 806)

Under all operating conditions, air enters the intake manifold through the throttle valve into the throttle body. However, on Citroen and Peugeot vehicles equipped with Bosch Motronic MP3.2, an induction changeover valve is used to improve air flow into the engine at both low and high engine speeds (see illustration 11.31).

Induction Changeover Valve (ICOV) voltage values

Terminal numbers

See illustrations 11.2, 11.3, 11.4, 11.5, 11.6

Inductive Changeover Valve (ICOV) Resistance Values

Terminal numbers

Induction Changeover Valve (ICOV) Testing (general check)

1. Inspect the induction changeover valve multi-pin connector for signs of corrosion or damage.

2. Make sure the contact pins of the multi-pin connector terminals are installed properly and have good contact with the induction switching valve.

3. Check the vacuum hoses for leaks and make sure they are securely fastened.

[Original can be viewed at peugeotbook]

Testing the performance of the induction changeover valve (ICOV)

1. Connect the negative probe of the oscilloscope or voltmeter to ground on the engine.

2. Connect the positive probe of an oscilloscope or voltmeter to the wire attached to terminal No. 2 of the induction switching valve.

3. Turn on the ignition. The voltmeter should indicate the nominal voltage of the battery.

4. If there is no voltage, check the supply voltage from terminal No. 5 of the main relay.

5. Connect the positive probe of the oscilloscope or voltmeter to the wire attached to terminal No. 1 of the induction switching valve.

6. Turn on the ignition. The voltmeter should indicate the nominal voltage of the battery.



7. If there is no voltage, check the resistance of the induction switching valve.

8. Start the engine and let it idle. The voltmeter should show a voltage of less than 1.0 volts.

9. If the voltage from terminal 8 exceeds the rated battery voltage, the following I/C valve tests should be skipped.

10. Check the continuity of the wiring back to the ECU pin #6.

11. If the wiring of the induction switching valve is OK, then check the power and ground contacts of the electronic control unit. If the contacts are in working order, then the electronic control unit may be faulty.

12. Increase the engine speed above the specified rpm. The voltage should increase from less than 1.0 V to the nominal battery voltage.

13. If this is not the case, the electronic control unit may be faulty.

14. Gradually increase the engine speed above the specified maximum rpm. The voltage should decrease by less than 1.0 volts.

15. If this is not the case, the electronic control unit may be faulty.

16. Check the mechanical operation of the induction changeover valve.

Testing the resistance of the inductive changeover valve (ICOV)

1. Disconnect the electrical multi-pin connector from the induction changeover valve.

2. Connect an ohmmeter between the two terminals on the induction switching valve. Compare the obtained value with the resistance specified in the specifications.

3. Connect an ohmmeter between one of the two terminals on the inductive switching valve (ICOV) and the ICOV body. The ohmmeter should indicate infinite resistance.

Checking the mechanical operation of the induction changeover valve

1. Disconnect the electrical multi-pin connector from the induction changeover valve.

2. Disconnect the two vacuum hoses going to the induction switching valve.

3. Connect the vacuum pump to the inlet pipe.

4. Using a pump, create a vacuum in the inlet pipe. The created vacuum must be maintained.

Note: If you don't have a vacuum pump, try blowing out the pipe. The attempt must fail.

5. Connect a temporary jumper wire from one terminal of the induction switching valve to the positive terminal of the battery.

6. Connect a temporary jumper wire from the other terminal of the induction switching valve to the negative terminal of the battery.

7. Using a pump, create a vacuum in the inlet pipe. The vacuum created should not be maintained, and it is now possible to purge the intake pipe to the exhaust pipe.

Checking the operation of the ICOV control valve

1. Disconnect the vacuum hose from the ICOV control valve.

2. Connect a vacuum pump to the inlet pipe of the ICOV control valve.

3. Create a 300 mmHg vacuum for the ICOV control valve. The control valve should move quickly and smoothly to fully open the ICOV flap.

4. Remove the vacuum. The control valve must move quickly and smoothly to fully open the ICOV valve.

5. Connect the vacuum hose to the ICOV control valve.