Checking the ground terminal

WARNING: This page is about a different car, the 2004 Volvo S40, 2003 Volvo S40, 2002 Volvo S40, 2001 Volvo S40, and 2000 Volvo S40. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Ignition OFF

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Ignition off.
Switch of all power consuming components, such as the passenger compartment lighting and the radio.
Connect an ohmmeter between terminal 16 on the breakout box and the battery negative terminal.

Fig 2: Breakout Box
Courtesy of VOLKSWAGEN UNITED STATES, INC.

Fig 3: Identifying Ohmmeter
Courtesy of VOLKSWAGEN UNITED STATES, INC.

The ohmmeter should read approximately 0 Ω.

OK
Refer to Checking the signal cable
NOT OK
Refer to Checking for an open-circuit and contact resistance