Bi-Pressure System Troubleshooting

When the key is turned in the master activator, all locks should be activated within 2 seconds. A fault is indicated if the pump runs longer than 5 seconds, or if any of the locks do not activate. Replacement hose is available from an authorized Volkswagen dealer. Troubleshooting should be carried out in the sequence given here, even if only one activator is suspected of being faulty. The replacement of faulty components is covered below under separate headings.

To troubleshoot:

1.	Remove the bi-pressure pump from its housing as described in Bi-pressure Pump.

2.	Clamp the hose as shown in Fig. 5-10. Activate the pump using the door key. If the pump runs longer than 5 seconds, either the hose from the pump is leaking, or the pump is faulty. If the pump shuts off within 5 seconds, remove the clamp and continue testing.

Fig. 5-10.

Bi-pressure pump being tested with hose clamp at 1.

3.	Clamp the hose as shown in Fig. 5-11. If the pump runs longer than 5 seconds, the left rear door activator or the hose to it is faulty. If the pump turns off within 5 seconds, remove the clamp and continue testing.

Fig. 5-11.

Left rear door activator being tested with hose clamp at 1, near hose distributor 2.

4.	Clamp the hose as shown in Fig. 5-12. If the pump runs longer than 5 seconds when activated, go to step 6. If the pump turns off within 5 seconds, either the right front or rear door activator, or the hose to them is faulty. Go to step 5. Remove the clamp.

Fig. 5-12.

Hose being clamped (1) in right rear of car. Clamp blocks air flow to right front and rear doors.

5.

To determine which right door activator is faulty, remove the right carpet trim strip and unscrew the lower B-pillar trim. Clamp the hose shown in Fig. 5-13. If the pump runs longer than 5 seconds when activated, the rear door activator or its hose is faulty. If the pump turns off within 5 seconds, the front door activator or its hose is faulty. Remove the clamp.

6.	Clamp the hose shown in Fig. 5-14. If the pump runs longer than 5 seconds when activated, then the rear lid activator or its hose is faulty. If the pump turns off within 5 seconds, the gas tank flap or its hose is faulty. Remove the clamp.

Fig. 5-13.

Hose being clamped (1) near lower part of B-pillar to block air flow to right front door.

Fig. 5-14.

Hose being clamped (1) in right rear of car to block air flow to gas tank flap.