Shortly after a recent recall of stalling Lexus and Toyota vehicles, the National Highway Traffic Safety Administration (NHTSA) is intensifying an investigation into almost 1.2 million 2005-2007 Toyota Corolla and Matrix vehicles that are experiencing similar stalling issues.
The safety agency began an investigation last November, but after Toyota provided additional information, the agency decided the problem was serious enough to upgrade the investigation to an “engineering analysis.” The agency said its concern is that “the engine can stall without warning at any speed and not restart.” It said it has 163 complaints from consumers, six of which reported accidents, but no injuries.
The investigation focuses on the Engine Control Unit module (ECU), the computer that controls the engine. The company said it did not consider the problem to pose “an unreasonable risk to motor vehicle safety.” But the automaker did note “we understand that some customers have been inconvenienced by engine E.C.U. failure and some have reported engine stalling.” Toyota told the safety agency there were two possible causes of the problem. One is cracks forming on the soldered joints of the control module’s circuit boards. The other is a defect in the coating applied to the circuit boards.
Toyota has also had problems with its electronic control modules in their 2001-2003 RAV 4′s. In March 2006, Toyota sent dealers a technical service bulletin about a transmission problems which caused harsh shifting that could damage the transmission.
The safety agency also has many stalling complaints from owners of the Pontiac Vibe — a mechanical sibling of the Matrix — but the documents detailing the investigation do not mention the Vibe.
