NHTSA Action Number: EA10006 Engine Stall
SUMMARY:
On August 26, 2010, Toyota submitted a Defect Information Report to the National Highway Traffic Safety Administration (NHTSA) regarding problems with Engine Control Modules that could result in engine stall while driving in certain model year (MY) 2005 through 2008 Toyota Corolla, Corolla Matrix and Pontiac Vibe vehicles equipped with the 1ZZ-FE engine and two-wheel drive and manufactured between April 19, 2004 and January 2, 2008. Toyota's report indicated that cracks may develop at certain solder point or on varistors on the ECMs. According to Toyota, such cracks generally resulted in engine warning lamp illumination, harsh shifting or engine no-start. In some cases, if the cracking occurs on particular solder points or varistors, the engine could stop while the vehicle is being driven. Toyota will notify owners of subject vehicles that they should return their vehicles to a Toyota or Pontiac dealer. Dealers will be instructed to inspect the production number of the ECM for each vehicle and replace the ECM if necessary. On November 30, 2009, the Office of Defects Investigation (ODI) opened a Preliminary Evaluation (PE09-054) to investigate alleged engine stall while driving in model year (MY) 2006 Toyota Corolla and Corolla Matrix vehicles. In its response to ODI's information request, submitted on March 2, 2010, Toyota indicated that it had identified two possible conditions with ECMs used in MY 2005 through 2007 Toyota Corolla and Matrix vehicles: 1) cracks forming between the IC and the board caused by an improperly cured conformal coating applied to the circuit boards after the soldering process is completed; and 2) cracks occurring in a variable resistor (varistor) due to overheating. During the manufacturing process a glass coating is created on the surface of the varistor. Between March and August 2010, Toyota began collecting ECMs from the field to further investigate failure modes that may result in engine stall. Toyota also conducted durability testing on ECMs collected from in-use vehicles to assess whether the problems may be a continuing trend. In addition, they conducted durability testing in order to assess whether this problem was a continuing trend. Toyota found that 4 of 32 collected ECMs malfunctioned after thermal shock testing. Toyota also confirmed that cracking could develop at solder points on the ECM circuit board that could lead to engine stall while driving and that this trend was likely to continue. The manufacturer failure data in this resume is limited to MY 2005 through 2007 Toyota Corolla and Corolla Matrix vehicles. Based on Toyota's recall, this Engineering analysis has been closed.
NHTSA Action Number: PE09054 Engine Stalling
SUMMARY:
On November 30, 2009, the Office of Defects Investigation (ODI) opened a preliminary evaluation (PE09-054) to investigate alleged engine stalling, while driving in model year (MY) 2006 Toyota Corolla and Corolla Matrix vehicles . In its response to ODI's information request submitted on March 2, 2010, Toyota indicated that it had identified two possible causes of production defects of the engine control units (ECU) used in the MY 2005 through 2007 Corolla and Matrix vehicles equipped with the 1ZZ-FE engine. Failure mode A1 - BGA ball failure caused by improperly cured conformal coating applied to ECU circuit boards. This can cause cracks to form in the soldered joints of some components. Failure mode A2 - Varistor over heating; a glass coating is created on the surface of the Varistor during its production process. In case of an insufficient coating, a crack can occur in the surface of the glass coating. When ions are charged in the plating electrolytes after the glass coating process, the plating electrolytes can penetrate into the Varistor through the glass crack then an electrical short occurs. With respect to these failures, if the condition arises, it can potentially lead to one or more of the following: MIL on, engine stall or engine no start, harsh shifting. Of the approximately 155,000 warranty and extended warranty claims Toyota has analyzed the projected 5 year failure rate of the ECU associated with an engine stall is 0.8%. This investigation has been upgraded to an Engineering Analysis (EA10-006) to further assess the scope, frequency and safety risks associated with the identified defects.
