According to Toyotas announcement, the drivers side switch may experience a notchy or sticky feel during operation. If commercially available lubricants are applied to the switch in attempt to address the notchy or sticky feel, melting of the switch assembly or smoke could occur and lead to a fire under some circumstances, Toyota stated.

Jason Galary, manager of technical support, applications, and engineering for Nye Lubricants in Fairhaven, Mass., said the fluorinated grease that Toyota will apply as part of the recall is an ideal choice for power window master switches.

Fluorinated [perfluoropolyether] grease is much more stable for higher temperatures, Galary told Lube Report. It probably wont start to break down and become more sludge-like until 250 or 300 degrees Celsius, and it can withstand large amounts of higher current applications with no problems. It is typically the route most switch designs will go for. The fluorinated grease also works well in environments where water might get in, he added. He noted that fluorinated PFPE grease typically plays well with other types of lubricants because it is extremely inert.

Galary emphasized its absolutely critical to get the lubricant where it needs to be on the switch. Making sure you have an even distribution of lubricant can be just as critical as having the right lubricant, he said.

In an Oct. 10 letter to the National Highway Traffic Safety Administration, Toyota confirmed that the grease application process in one of three production lines for the contact module was changed from a spray-type application to a squeeze-type application between August 2006 and June 2008.

In September 2008, Toyota received a field technical report from the U.S. market indicating an unusual smell coming from the switch and thermal damage on it. The master switch was returned to the supplier for investigation and analysis. The sliding contact module inside the master switch for the passenger side window was found to be carbonized but the root cause wasnt identified.

From May 2010, Toyota begin sporadically receiving field technical reports concerning abnormal smell and/or smoke coming from the drivers side door, especially near the master switch. When Toyota analyzed various returned master switches which had thermal damage such as melting and burning, electrical arcing and wearing of the contacts due to high, repeated operation was observed.

Carbonized material was also confirmed in the contact module, which could create a short circuit and lead to increased heat and resultant melting of the master switch. In addition, chemicals containing silicone or ester, which are found in common lubricants and cleaning products were present in most of the analyzed parts. Neither silicone nor ester is used in the manufacturing process for the switches.

Toyota also found that, in the squeeze-type grease application, the grease may be applied unevenly on the contact module terminals, Toyota stated. In this condition, frequent usage of the switch and normal arcing of the contact points may cause the grease to become carbonized and the contact points may prematurely wear, causing a sticky condition. If the switch is continuously operated with the sticky condition, it could result in the switch becoming inoperative.

The recall fix will involve an inspection, switch disassembly and application of special fluorine grease. A dealer will perform the switch inspection and repair at no charge to the vehicle owner. The repair will take approximately one hour depending on the dealers work schedule.

Owners of vehicles covered by the safety recall will receive an owner notification letter in late October.