917501 Operation and Diagnosis of the ParkAssist System (89/13): Tools

WARNING: This page is about a different car, the 2016 Porsche Macan and 2015 Porsche Macan. However, it is still accessible from the selected car via links, so may be relevant.

Designation	Type	Number	Description
PIWIS Tester III	Special tool	9900		Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Model year:

as of 2005

Vehicle Type:

All 911 Carrera models (991/997)

All Cayenne models (92A)

All Panamera models (970)

All Boxster/Cayman models (981/987)

All Macan models (95B)

Equipment:

ParkAssist

Concerns:

ParkAssist sensor

Information:

Accurate Diagnosis of ParkAssist .

As most of the ParkAssist sensors returned to Porsche after warranty replacement are found to be not defective, proper understanding of system operation and diagnostic measures must be reviewed.

Information

=> The system clearly and reliably detects a faulty sensor .

A fault code is stored in the fault memory of the ParkAssist control unit .

Operating Principle:

Information

Operating principle → Physical principles:

=> The "ParkAssist" system operates in the ultrasound range.

The sensor is used both as a transmitter and receiver:

An active sensor sends an ultrasound signal, which is reflected by an obstacle and is received again by the sensor.

The term ultrasound refers to sound waves with a frequency above the human hearing range . Ultrasound is not perceptible or audible.

=> Noises coming from directly around the vehicle can influence and even disrupt the system, but cannot necessarily be heard (by the human ear).

Examples of noises (even in the ultrasound range) and ambient conditions :

Pneumatic brake system on a truck,
Pneumatic hammers on a building site and
General squealing and whistling noises in the immediate vicinity of the vehicle .
Different layers of air (warm/cold), produced for example by exhaust gases from a vehicle or from a duct cover,
very dirty sensors or
iced-up sensors

can also impair the system.

=> Structural modifications to the vehicle, e.g.:

Badly painted sensors (e.g. paint applied too thickly),
License plate holders/transferable number plates,
Bent or inadequately secured license plates (particularly at the front) or
Add-on parts, such as spoilers, etc. from independent accessory stores (without Porsche approval)

can impair the system.

=> The system even works correctly if:

plants or
Curbs are detected .

Procedure:

Check the function of the "ParkAssist" system and sensors using PIWIS Tester III 9900 :

=> First select 'ParkAssist' control unit

=> then highlight the sensors to be checked in the 'Actual values' menu and

=> check the plausibility of the displayed actual values (distance to an obstacle).