DTC B2820: Relay, headlamp wipers: Circumstances

WARNING: This page is about a different car, the 2001 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.

The control module output is monitored and a DTC generated if there is a:

Open circuit or short to ground.
Short circuit to B+.

DTCs are not generated if the voltage is below 11V or during diagnostic communication.