One problem related to starter solenoid has been reported for the 2010 Toyota Highlander. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2010 Toyota Highlander based on all problems reported for the 2010 Highlander.
2010 Toyota Highlander caught on fire while parked in garage of residence, destroying the Highlander and the car parked adjacent to it, along with most of the house. Prior to the fire, there were no issues with the vehicle. The Highlander was stationary, with the ignition off and parked in the garage. A subsequent investigation including inspecting burn patterns and thermal damage indicated the fire originated at the front of the Toyota Highlander on the driver's side where the fuse panel, battery and starter/solenoid were located. All three sources of ignition remain energized with the ignition off. The upper portion of the plastic housing on the fuse panel and battery had melted exposing the receivers for the fuses and plates inside the battery. The ends of the receivers had alloying on the receivers, but no failures were noted on fuse panel or battery. Extreme thermal damage was observed on the connector end of the solenoid where most of the facing had melted or was consumed. Lines of demarcation from extreme heat was observed on the remaining section of the solenoid facing. The cable connecting the battery to the solenoid was not connected to the solenoid due to the extreme damaged to the solenoid. The terminal connector on the cable sustained arcing and/or melting of the metal terminal. The conclusions were that the fire was caused by a failed solenoid attached to the starter on the 2010 Toyota Highlander. Lab analysis of the starter/solenoid revealed failure at the connection end of the solenoid with beading and arcing on contacts inside the solenoid.