Linsheng Examples Of Automotive Secondary Air Pump Problems
Due to the secondary air pump problem, Subaru recalled part of the Legacy
Recently, Subaru Automobile (China) Co., Ltd. filed a recall plan with the General Administration of Quality Supervision, Inspection and Quarantine, and will recall some of the imports from July 31, 2009 to June 7, 2012, starting from March 20, 2018. The 2012 Legacy series of cars. According to the company’s statistics, there are 3,396 vehicles in mainland China.
Some vehicles within the scope of this recall have incorrectly indicated the contents of the maintenance operation method for the secondary air pump relay defect recall issued on November 1, 2016, and the relay may be installed in the wrong state during the recall operation. The position, failure to eliminate the original defects, may cause the resin parts to melt, emit odor and smoke, and even catch fire, there is a safety hazard.
Subaru Motors (China) Co., Ltd. will replace the modified secondary air pump relays for the vehicles within the scope of the recall according to the correct maintenance method, and check the relays in the previous installation position. If the installation is wrong, correct it to eliminate the defects. .
If the relevant user finds that the engine warning light is on, the engine compartment cover is smoking, and the odor is emitted, the vehicle should be stopped immediately and contacted for sale. The user should contact the dealer for repair as soon as possible after the recall operation begins.
The position of the secondary air pump relay indicated in the maintenance operation instruction book issued by the secondary air pump recalled and implemented on November 1, 2016 is in line with the actual layout of the vehicle, and the secondary air pump relay is installed in the correct position. Not affected by this recall.
linsheng said: The working principle of the secondary air pump is to use the air pump to send fresh air to the base of the engine exhaust manifold, that is, the connection between the exhaust manifold and the cylinder head, so that the carbon monoxide/hydrocarbon contained in the exhaust gas is discharged from the exhaust gas. The gas manifold is further oxidized and burned at the beginning, and the oxygen in the fresh air reacts with the carbon monoxide/hydrocarbon in the exhaust gas in the exhaust pipe to be converted into steam/carbon dioxide, thereby reducing the exhaust gas during cold start of the vehicle. emission.
It is well known that the mixture of the vehicle during cold start is richer than the mixture at the normal operating temperature of the engine, so as to ensure smooth and smooth operation of the engine, and the oxygen sensor and three-way catalysis of the vehicle in the cold start state. The normal operating temperature is not reached, so the exhaust gas monitoring and exhaust gas catalytic conversion are not optimal. The fresh air and exhaust gas sent to the exhaust manifold by the secondary air pump are reoxidized and burned, which is also beneficial to the oxygen sensor and the three. The elemental catalysis is heated up to the normal working temperature as soon as possible to achieve the best working conditions, promote the catalytic conversion of the exhaust gas, and reduce the emissions.
In addition, the secondary air injection system can supplement or burn the exhaust gas in the exhaust manifold, which can also reduce or avoid the occurrence of Mars in the exhaust gas, and reduce the fire hazard in a special environment.
Generally speaking, the working time of the secondary air pump is relatively short, and its working state is affected by the engine temperature/speed, etc., and usually the secondary air pump is operated for between 2 seconds and 60 seconds.
Subaru (China) started the recall activity because of the contact sticking failure of the secondary air pump control relay, which caused the secondary control pump to continue to operate and eventually burned or even caught fire.