What if Buick LaCrosse 2.4 displays fault code P00 14?

● Fault phenomenon: A Buick LaCrosse (model 06, 2.4L) has traveled 6.5438+0.5 million kilometers. When I arrived at the maintenance station to maintain the engine, the fault light came on, and the TC (traction control) light came on, so I couldn't afford to refuel, and the gear shift had an impact. \x0d\● Diagnosis process: Diagnose the fault with TECH2. The fault codes are P017 (crankshaft position-exhaust camshaft position correlation), P014 (exhaust camshaft position system performance) and C0240 (engine control module disables traction control system). During the test run, it was found that the shift was obviously shocking, and the engine power was obviously insufficient when driving and refueling. After clearing the fault code, try again, and the gear will not impact. After driving 15km, the engine fault light will light up, the TC light will light up, and the computer will detect the fault code as before. \x0d\● Principle analysis: The car is equipped with a four-cylinder engine, code LE5, VVT (variable valve timing mechanism). P00 17 and P00 14 are related to the VVT system. \x0d\ The following figure shows the working principle of camshaft in VVT system of LE5 engine: \ x0d \ figure1\ x0d \ Figure2 \ x0d \ Figure3 \ x0d \ Figure4 \ x0d \ Figure5 \ The work of the camshaft position actuator is mainly based on the signal received by the camshaft position actuator solenoid valve from the engine control module. The solenoid valve controls the amount of engine oil flowing to the camshaft position actuator for hydraulic operation, so that the camshaft position actuator can drive the camshaft to change the angle. \x0d\● Maintenance process: According to the principle analysis and maintenance manual, related factors include camshaft position actuator solenoid valve, actuator, line and oil pressure, oil circuit blockage, etc. \x0d\ 1, according to the preliminary analysis and simple judgment, eliminate the line fault. \x0d\2。 Replace the exhaust camshaft position actuator and the intake camshaft position actuator, clear all historical fault codes, and then test run. After dozens of kilometers, no fault was found. Two or three days after delivery, the customer informed that the fault light was on, but the phenomenon was not as obvious as before. \x0d\3。 After returning to the factory, the fault codes are P00 17 and C0240. Then read the maintenance manual carefully and ask the maintenance personnel. The maintenance instructions found that the spilled oil was dirty when the actuator was disassembled. So will the oil circuit be blocked because of dirty oil? After discussion, the customer is advised to clean the oil pipe and change the oil. \x0d\4。 Clean the lubrication system, and the discharged oil is particularly dirty. After the oil change, it was tested again, and no abnormality was found. Let the customer go back and try again, and no customer reported an error after that. It means that the fault has been eliminated. \x0d\● Summary: Later, several vehicles with similar faults were repaired one after another. The characteristics of these cars are * * *: most of them are foreign cars, so they can't come to the 4S shop for maintenance, but they are repaired in the local small repair shop, and the quality of the replaced oil is not good, and the replacement interval is too long. This will easily generate coke in the oil, thus blocking the screen leading to the camshaft position actuator. There are many fault codes related to VVT, such as P00 10, P001,P00 12, P00 13, P00 14 and P0014. \x0d\ As for the TC light, the engine control unit instructed the throttle actuator control system to work in the "reduced engine power" mode, which caused the traction control system to turn off the indicator light (C0240). The impact of gear shifting is caused by the lighting of TC lamp.