XQ w9d3nx
+Wg:`#[*OX"kY
Applicable model: W 140 * K/V5Wu \
One of the fault phenomena: the acceleration of the vehicle is poor, and the maximum speed can not be reached! Iaa！ ?
Preliminary analysis of fault causes
1. Engine system power is insufficient. k，a $ F & ampo9X，v+L
2. Electrical failure of gearbox system.
3. The transmission parts of the gearbox system slip.
fault diagnosis
1. Turn off the ignition.
2. Connect the automobile computer fault diagnosis instrument (HHT original Mercedes-Benz instrument, START2000 or other brand equipment). { SMh0_[*J
3. Turn on the ignition or start the engine. C \ C\C{^ University! t 1G B0}
4. Use the original instrument HHT of Mercedes-Benz and select the "HFM/ME2" menu of the engine system for fault detection. Generally, the diagnosis results are: the system has no fault memory or fault code P0 100, and the signal of hot film air flowmeter is faulty. This fault code can be cleared, and it will not appear again when the engine is running again. ! k)N/r 1uhx
If the P0 100 fault code appears again, the hot-film air flowmeter must be replaced. After a road test, the fault can generally be eliminated. Ku*J B"}*}
5. If the engine system has no fault memory, use the original instrument HHT of Mercedes-Benz and select the "EGS/AGS" menu of the chassis system to detect the computer fault of the gearbox. The general diagnosis results are: the system has no fault memory or fault code 55/ 15 1, the shift lever position is incorrect or the transmission parts slip. This fault code can be cleared and reappeared when the engine is running again and the road test, so check the transmission parts of the gearbox.
Automatic transmission oil quantity check
Use A/T special dipstick (not included in the original car, it must be purchased separately) to measure the oil level. If the oil level is insufficient, it must be topped up; If the oil level is too high, the excess must be drained. D/ s' [Z
A/T engine oil quality inspection BJ%n t n|! na，T]！ b
While checking the oil level, you can also check the oil quality. If there is a burning smell, the oil pan must be disassembled for comprehensive inspection, and the gearbox assembly must be disassembled if necessary. D+cM6v]:JV？ ! Quantitative easing: f
Transmission assembly inspection 4l]|#GW7VtUk#T
Mercedes-Benz 722 gearbox has scientific structure and convenient disassembly. Usually, the fault location is the wear of the 5th overdrive clutch plate. Xu&XTC-G3?
Maintenance summary, sL[.vN8Z]
1. Standard parameter x`Wru of hot film air flowmeter signal.
Test conditions: after the engine is warmed up (water temperature >; 85℃) fault-free code memory, all electrical equipment such as air conditioning system, light switch, front/rear glass window heating, etc. When the throttle is in the idle position and the gearbox is in the P position, it must be closed. IM@ V+`xUz
When the equipment test data is 16 ~ 18 kg/h, the air intake system leaks. If it is greater than 16 ~ 18 kg/h, it indicates that the engine load is too large or the air-fuel ratio of the engine system is not matched. ; U3\^EC7^ 1MIf
2. When the hot film air flowmeter fails, the engine control computer will not have fault code memory for a short time. If the line is short-circuited or open-circuited, the engine control computer will immediately remember the fault code. This is the lack of fault monitoring program for engine control computer. F V } @ 7ah$}9E6r
The second fault phenomenon: when the vehicle is in R or D gear, it is sometimes impossible to start and shift gears while driving, with a top speed of 50km/h, commonly known as "locking gear".
A preliminary analysis of the causes of failure. RRz，_/`|
1. Electrical failure of gearbox system. Qe^
2. The transmission parts of the gearbox system slip. b`,K%HXC，mx[
Fault diagnosis kzC/]b U{B
1. Turn off the ignition switch.
2. Connect the automobile computer fault diagnosis instrument (HHT original Mercedes-Benz instrument, START2000 or other brand equipment).
3. Turn on the ignition or start the engine.
Select the "EGS/AGS" menu of the chassis system to detect the fault of the gearbox computer.
The fault code of diagnosis result is:
55/ 15 1, the shift lever position is incorrect or the transmission parts slip.
12, speed sensor N2
13, speed sensor N3 v lW e3B%}w, `v
The fault code can be cleared and the engine will not run again. However, if fault code 55 and 15 1 appear again during the road test, the transmission parts of the gearbox should be inspected.
4. It is found that the transmission assembly of the gearbox is worn on the clutch plate of 1 gear. After the replacement, the road test showed the failure phenomenon and there was not much improvement before the maintenance. However, the vehicle starts powerfully, and there is no fault code memory, indicating that the slip phenomenon of transmission parts of the gearbox has been repaired. z^,D5AR-n2x~！ e
At this point, the maintenance work is in a dilemma. After the equipment test, the working parameters of the sensor are within the specified range, and there is no problem. Finally, the fault points are concentrated on the transmission oil valve body and the control computer.
6. Because the gearbox control computer is convenient to install, it should be disassembled for inspection first. It's weird when you unplug the two plugs of the gearbox computer! Why are there oil in the two plugs of the gearbox computer? Take a closer look. This is ATF oil.
7. How did the transmission ATF oil get into the transmission computer? The reasons may be as follows:
1) The gearbox vent (dipstick) is blocked;
2) There is too much ATF oil in the gearbox. Because the oil pressure in the gearbox is too high, ATF oil slowly penetrates into the environmental protection glue of the solenoid valve harness. ; V~"bkf/g3W%lG
8. The gearbox computer is soaked with ATF oil, so replace it first. Re-program the new gearbox computer with the automobile computer fault diagnosis instrument (HHT original Mercedes-Benz instrument, START2000). After the road test, everything was all right.
9. The computer programming method of gearbox is as follows:
1) Turn off the ignition switch. ，Jj4s5|f"E
2) Connect the automobile computer fault diagnosis instrument (Mercedes-Benz HHT original or START2000).
3) Turn on the ignition switch. L7X4Z's T4H
4) Select the EGS/AGS menu of the chassis system to detect the fault of the gearbox computer. v(@G 1_3c/o2hB7q
5) When reading the system fault memory, it should be normal. /_ W & amp； I0I%sk
6) Select "Control Module Adaptation" to control the computer matching menu.
7) Select the "Programming" programming menu after confirmation. ~6o！ ru2rO
8) After confirmation, the equipment prompts to turn off the ignition switch, replace the old computer, and turn on the ignition switch again after replacing the new computer. 0I`bOJ M2nu！ j^r&； z}
9) After confirmation, the programming will proceed automatically. N2~:TCBmqK
10) The device prompts to turn off the ignition switch and turn on the ignition switch. #IyW6TU6N(O@)
1 1) after confirmation, the device prompts to read the version number. After confirmation, the version number is e44. Programming is complete.
Maintenance summary
1. The test instrument must be available. & ampkL z & ampV+a
2. A/T special dipstick must be prepared. If there is too much A/T special oil, burn the computer; If the A/T special oil is less, the gearbox will burn out the clutch plate because of the lack of oil.