Can't Haval H6 transmission increase its speed in time after upshifting?

A Great Wall Haval H6 sport utility vehicle with a mileage of about 65,438+00,000 km is equipped with a 6-speed automatic transmission. User feedback: After the transmission is upshifted, the vehicle speed cannot be increased in time, and the engine speed decreases after the upshifting period reaches about 4 000 r/min, so the vehicle has obvious frustration at the moment of gear shifting.

Inspection and analysis: after receiving the car, the maintenance personnel first conducted a trial run and found that everything was normal when the car was upgraded from 1 2. During the shift from 2nd gear to 3rd gear, the gear position on the instrument panel has been displayed in D3, at which time the engine speed instantly increased to about 4 000 r/min, and then the engine speed returned to normal. The vehicle has obvious frustration at the moment of successful gear shifting. When the third gear rises to the fourth gear, the fourth gear rises to the fifth gear, and the fifth gear rises to the sixth gear, the fault phenomenon is the same. Manual mode has the same fault phenomenon, and there is no fault light on the instrument panel.

When the vehicle is detected by the diagnostic instrument, it is found that there are several fault codes: P168300-the communication information of airbag is unreasonable; U0 15 187-ECU lost communication with ABM; P056400 cruise button viscous cruise input voltage value is unreasonable, and the difference between two sampling voltages of cruise module is too large; P 16 1300- wrong transponder key.

From the fault code analysis, it is considered that these fault codes have little to do with the fault of this car. The fault still exists after clearing the fault code. Lift the vehicle, and check whether the oil quality and color of the transmission are normal, and whether there are signs of burning or water ingress. Start the vehicle, open the observation port bolt, and no transmission oil overflows, indicating that the transmission oil is insufficient. After adding about 0.3 L transmission oil, the fault is still the same.

Test the stall of the vehicle. In the idle state, press the brake pedal, shift to D gear, and quickly press the accelerator pedal to the bottom. At this time, the engine speed can reach 2 200 r/min, and the stall test is normal, indicating that the engine power is normal and the torque converter and clutch do not slip. When reading the transmission data stream during the road test, it is found that the "throttle angle" in the data stream is always 0, and the throttle angle of normal vehicles will change with different vehicle working conditions. Check the throttle valve, and no abnormality or sticking is found. After cleaning the throttle, the road test shows that the fault still exists.

At this time, the maintenance is deadlocked. Read the engine fault code again. The previous fault code P056400 still exists. The cause of this fault code should be a problem with the cruise switch or the wiring from the switch to the ECU. Check the left A-pillar harness connector. No trace of water was found. Press the cruise control switch, the cruise control indicator light on the instrument panel will light up and the cruise control function will be turned on. Press the cruise control button again, the instrument cruise indicator will go out and the cruise control function will be turned off. Other buttons, such as cancel, set and res, were tested one by one, and all the buttons in the cruise were tested to be normal during the road test. During the road test, when the transmission upshifts, the engine speed will not increase and the shift will not be smooth. When the transmission data flow is checked during driving, the "throttle opening" will also return to normal. Because the user is in a hurry to use the car, let the user drive the car first, and then check at the store at any time if there is any problem.

A few days later, the user came to the store again, indicating that the fault appeared again. After consulting the relevant maintenance cases, the maintenance personnel found that the signal duration of the constant-speed cruise switch of this model exceeded 6 s, and ECU would think that the cruise switch was stuck and entered the constant-speed cruise fault mode, which delayed the shift, so the shift speed was high and the shift was frustrated. After communicating with the user, I learned that I accidentally spilled some on the steering wheel while drinking in the car some time ago, but I dried it in time and didn't care too much. This is probably the cause of the failure, because the cruise control switch was spilled with drinks, and the user accidentally touched the cruise control switch while driving, which led to the failure.

Troubleshooting: After replacing the cruise control switch, troubleshoot.