Description of On-Board Diagnostics

General Information

The Acoustic Parking System (APS) monitors the vehicle's environment via four ultrasound sensors in the front bumper and four ultrasound sensors in the rear bumper. The acoustic gap notification is given via one chime in the front and one in the rear of the vehicle interior.

There are four ultrasound sensors built into each of the bumpers, front and rear. The sensors can be controlled in either the combined send/receive mode or in receive mode alone.

The rear sensors are switched off if a trailer hitch is attached and the trailer plug is connected. The front sensors remain active.

The gap warning starts during reverse or forward driving (acoustic parking system active) at:
- less than approx. 60 cm on all side sensors
- less than approx. 120 cm for front-center sensors
- less than approx. 150 cm for rear-center sensors

Function:
The Acoustic Parking System (APS) consists of:

- Control module for parking aid -J446-
- Right front parking aid sensor -G252-
- Right front center parking aid sensor -G253-
- Left front center parking aid sensor -G254-
- Left front parking aid sensor -G255-
- Left rear parking aid sensor -G203-
- Left rear center parking aid sensor -G204-
- Right rear center parking aid sensor -G205-
- Right rear parking aid sensor -G206-
- Front parking aid warning buzzer -H22-
- Warning buzzer for parking -H15-
- Switch for parking assistance with integrated function lamp (LED)

After switching ignition on, a self-test is performed that is completed in less than a second. The control module is now permanently in operation, but gap recognition is only activated once reverse gear is engaged or can be activated/deactivated with the switch for parking assistance.

When parking assistance is ready, a short signal is sounded (delay of one second for automatic vehicles due to P-D shift) and the function lamp in the switch lights up. If a malfunction is detected in the system, a constant signal sounds for 5 seconds and the function lamp in the switch for parking assistance blinks.

The pauses between chime impulses get shorter as the gap between vehicles gets smaller. For gaps under 25 cm, the chime becomes constant. (volume and pitch (frequency) can be adapted using the VAG1551).

Special case: driving along a wall


NOTE: The following description refers only to the VAG1551 Scan Tool (ST).