Subaru 31918AA000 Automatic Transmission Inhibitor Switch

Lift the vehicle onto jackstands and locate the backup light and Neutral Safety Switch on the transaxle's left side. Trace the electrical lead to its connector, unplug it, and connect an ohmmeter to the terminals. Check for continuity in reverse for the backup light switch and Neutral for the Neutral Safety Switch. If it does not work, replace it by first unscrewing the old one. Install a new one and secure it. Verify the new switch's functionality and reconnect the electrical connector. Finally, lower the vehicle.

Raise the vehicle and support it securely on jackstands, the back-up light switch and Neutral Safety Switch are located on the left side of the transaxle, on turbo models, remove the inter cooler. To check either switch, trace the electrical lead back to its connector and hook up an ohmmeter. To check the back-up light switch, put the transaxle into reverse and verify that there's continuity (zero or low resistance), then put the transaxle in any other gear and verify that there's no continuity (higher infinite resistance). To check the Neutral Safety Switch, put the transaxle in Neutral and verify that there's continuity (zero or low resistance), then put the transaxle in any other gear and verify that there's no continuity (high or infinite resistance). If either switch fails to operate as described, replace it by unscrewing and removing the old switch, installing the new switch (make sure the washer is installed) and tightening it to the torque, then plugging in the electrical connector and verifying that the new switch works properly.

Remove the center exhaust pipe section and on later models the front part of the exhaust system.

The TR sensor is located on the right side of the transaxle.

Installation is the reverse of removal.