I2 Checking the Auxiliary Air Valve

I2 Checking the auxiliary air valve

Tools:
- Multimeter
- Torch
- Mirror or sheet of white paper

Before starting to check the auxiliary air valve, unplug the control module and auxiliary air valve connectors.

Note: Checking is to be carried out when the engine is cold (below 30°C / 86°F).

1 Using two separate jumper leads with crocodile clips, connect pin 21 (yellow/white; GL/VT) and pin 17 (violet; VL) of the control module connector to ground.




2 Check that voltage is present across the pins in the auxiliary air valve connector. If it is not, check the operation of the main relay and pump relay, see sections E1 and E2, and the grey and black (GR and SV) leads to the auxiliary air valve.

3 Detach the rubber hoses and plug in the auxiliary air valve connector. Check that the valve opens by shining the torch through one of the hose spigots and holding the mirror or sheet of white paper close to the opposite hose spigot. The valve should close fully after about five minutes (depending on engine temperature).

4 If it does not, check the resistance of the auxiliary air valve by connecting the multimeter test prods to its pins. The resistance should be 40-60 ohms.

If this reading is not obtained, fit a new auxiliary air valve.