Issue: The Lexus ES350 sedan has 136,000 miles and is fitted with one-key smart start and smart boarding functions. Customers say they can't utilize the smart car system normally.  Diagnosis: Start the vehicle without using the smart key to approach the ignition switch, indicating that the smart entry system is not turned off (can be set to turn off), turn the vehicle power mode to OFF state, press the smart key to lock and unlock Switch, it is discovered that the vehicle can be unlocked and locked normally, without any abnormalities, the vehicle will be unlocked. The vehicle could be...

[Model: 2014 Audi A7 Coupe. Driving mileage: 37282miles. Issue: Multiple fault lights suddenly light up during driving, with ABS, tire pressure monitoring and air suspension all illuminated. The fault remains after the car is turned off and restarted. Diagnosis: First, connect to VCDS and enter 03 detection, the fault code is 0365 of the right front wheel speed sensor, the fault code is shown in Figure 1.   Figure 1 Turn the right front wheel once the wheel is off the ground, and the wheel speed as well as forward and backward status can be displayed normally in the data...

Model: Audi A6L, equipped with BPJ engine and 01J transmission.Driving mileage: 79684km.Trouble phenomenon: The customer's vehicle shakes severely after starting, and the vehicle is towed to our service station.After inspection by the maintenance technician, it was found that the camshaft of the vehicle had been slightly locked and the engine needed to be repaired. The customer did not agree to the repair and directly asked us to replace the engine assembly, as shown in Figure 1. Figure 1 Replace the engine assembly  After the engine was replaced, it was handed over to the customer for use. On the third day,...

Model: Equipped with M271EVO engine. VIN: LE42121471L××××××. Issue: The customer reported that the engine fault light was constantly on, and after which, the engine was sometimes weak. Diagnosis: Inspect the vehicle after getting it according to the customer's description. The technician started the engine and discovered that the engine warning light on the instrument was always on; the operating condition was checked while the engine was idling, and no visible abnormalities were discovered. Confirm the failure that the customer has reported. The technician then connected to a Mercedes-Benz special diagnostic equipment to read the relevant fault code, which revealed that...

Model: Equipped with U151E/F automatic transmission. Issue: Highlander 2nd to 3rd gear shock. Diagnosis: When the vehicle accelerates hard, a forced downshift occurs from 3rd to 2nd gear. As speed increases, and when the throttle is removed, the engine load is lessened. The vehicle will shift from gear 2 to gear 3 (the typical car upshift will be seamless if you don't step on the accelerator), but if you accelerate engine load will increase, and the engine and transmission computer will change gears. When overtaking, the car will automatically shift to a lower gear. If the U250E transmission is in...

[Repair Case] Lumina can’t drive at high speed Model: 3.1L engine and automatic transmission. Issue: When the car is operating, the driver reports that it becomes harder to increase the speed even if the accelerator pedal is depressed. The vehicle's top speed is limited to 44 miles per hour. After inspection by maintenance staff the defect is assumed to be the automatic gearbox lock. The automatic transmission system is in good working order, transmission oil is adequate, and the internal friction components are not overly worn or burned. Diagnosis: A stall test was performed. The drive gear has a stall...

Issue: The car was towed to the repair shop for maintenance because it wouldn’t start. The preliminary inspection result showed that there was a high-pressure fire, but there was no fuel injection. Troubleshooting:  The engine is equipped with a HEI-EST ignition system, which stands for high-energy electronic ignition. For the fire test, we unplugged the sub-cylinder high-voltage cable to test for firing; the sparks were very strong. Next, we used chemical cleaner into the intake manifold, and the engine could barely operate. We used an external pump instead of the fuel pump of the original car to build up the...

Model: Audi A6, equipped with 2.4L engine. Driving Mileage:31068 miles.  Issue: According to the driver, the engine is prone to stall failure during the driving process after warming up, and it is difficult to restart the vehicle after stalling.  Troubleshooting: There is no failure code when using the Chinese V.A.G1551 diagnostic tool to self-diagnose the engine control system. When starting the engine, it runs smoothly at idle speed in idling conditions. There was no visible aberrant data when it was examined. The problem is considered to be in the engine fuel delivery system, based on the fault characteristic mentioned by...

Make: Porsche Model: Cayenne. Mileage: 168,365 miles The gear display of the Porsche Cayenne is abnormal. Troubleshooting: Verify the fault after connecting the car. As stated by the customer, the diagnostic instrument detects that the transmission reports a fault, and the selector lever switch is grounded. Modules related to gear display include transmission control unit, gear switch, gear selector switch, and transmission valve body control unit. The gear selector switch is located under the cover of the gear lever. After disassembling, it is found that there are obvious traces of water ingress. Measure according to the circuit diagram and find...

[Repair Case]: 520Li Fuel Pump Control Regulation Voltage Faulted Issue:  A 2011, BMW 520Li, model F18, with an odometer reading of approximately 25,000 miles. The vehicle was unable to accelerate while driving, and the user noted that the motor shook severely after stopping, before turning off the engine. The instrument's engine fault light illuminates, signaling a problem, and the central information display reads, "The engine power is down, the fuel system has something wrong!" The vehicle can be re-started and driven normally after it has been parked for a period of time.  Diagnosis:  Observe that the engine runs smoothly in...

[Repair Case] A Cadillac’s front wheel and steering wheel shake while steering. Car Series: Cadillac Model: SRX/Kay Leide System: Chassis Issue: When faced with a fast steering or a large turning angle, the front wheel generates a gap brake, and the steering wheel shakes. Diagnosis: Checking the brake mechanism and steering mechanism of the vehicle, no looseness was found. Using car code reader to check the electronic stability system, we got the following error codes: C0460, C046. They indicate ranges for the steering wheel position sensors. Re-entering the data system analysis, it turned out that the steering angle measured by...

Make: BMW 520Li Model: F18. Driving mileage: 49,710 miles Trouble phenomenon: The user reported that the instrument steering system failure warning light was on when the vehicle was driving, and the central information display screen prompts "Steering system, please drive carefully!" When turning the steering wheel, the turning becomes very heavy. Fault diagnosis: Upon inspection, the issue is confirmed, the EPS fault alarm lamp on the instrument panel continues to light up to give an alarm. When turning the steering wheel, the feeling is very heavy, and not assisted. Connect ISID for diagnostic testing, the EPS displayed in the diagnostic tree...