Tire Pressure Monitoring System (TPMS) system failure icon.  Based on icon shown in U.S. National Highway Traffic Safety Administration (NHTSA) Notice of Proposed Rulemaking, Docket No. NHTSA 2004-19054.  See http://www.nhtsa.gov/cars/rules/rulings/tpmsnprmpost2cir/tpmsnprmpost2cir.html
Own work
Hydrargyrum