Failure Analysis of Polaris Car Assist Brake Vacuum Pump
June 26 08:05:49, 2024
A 2004 Polaris 1.8L comfortable sedan, the car owners found the car came abnormal sound. Repair mechanic found the auxiliary brake vacuum pump long-term non-stop operation, and occasionally will stall for a few minutes. Polaris equipped with a controlled vacuum pump, engine control unit based on the engine load, speed, throttle position and brake light switch signal to calculate the brake booster pressure, and then with the engine control unit intake manifold pressure model In contrast, decide whether to turn on the vacuum pump. The car may be abnormal sound controllable vacuum pump some part of a fault. Connect VAS5051, enter 01 address, read the fault code with 02 function, there are 3 permanent fault codes that can not be cleared. They are fuel tank vent valve N80 fault, air flow meter G70 fault and oxygen sensor heater fault. Visually found that the car fitted with anti-theft devices and reversing radar, and the anti-theft horn was a long self-tapping screw on the firewall, the long screw piercing the main control unit of the engine power bundle and make One of the lines cut the ground. Check the circuit diagram that this line is the air flow meter, tank vent valve and oxygen sensor heating coil power supply, three lines share a fuse S243, after checking the fuse has blown fuse blown fuse failure, Cause air flow meter, tank vent valve, oxygen sensor heating coil no working power. If the engine ECU does not receive the load signal (air flow meter signal), and after comparing with the standard data, it will consider the vacuum pressure in the brake is insufficient, thus controlling the auxiliary brake vacuum pump to work, resulting in the above malfunction. Re-banding finishing lines, and then start the test, the fault code can be cleared, and no longer reproduce, auxiliary brake vacuum pump is no longer frequent movements, fault completely ruled out. In troubleshooting, the idea must be open, especially when several fault codes appear at the same time, and can not be cleared, usually have a certain relationship between them, so to use the method of thinking to analyze.