FixVault

Check Power Supply And Ground Circuit

WARNING: This page is about a different car, the 2005 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.
CHECKING POWER SUPPLY AND GROUND CIRCUIT

Step Check Yes No
1 : CHECK POWER SUPPLY. 
  1. Disconnect the keyless entry control unit harness connector.
  2. Measure the voltage between the harness connector terminal and chassis ground.

Connector & terminal 
(B176) No. 14, No. 15 (+) - Chassis ground (-): 
Is the voltage more than 10 V? Go to step 2.  Check the harness for open circuits and shorts between the keyless entry control unit and fuse.
2 : CHECK GROUND CIRCUIT. 
Measure the resistance between the harness connector terminal and chassis ground.
Connector & terminal 
(B176) No. 11 - Chassis ground: 
Is the resistance less than 10 ohm? The power supply and ground circuit are OK. Repair the harness.