◆ ◆ runs quickly E200 air conditioning does not have law refrigeration
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(1) breakdown symptom
Model of this car batholith is W211, configure M272 engine. Air conditioning system not refrigeration, and appearance stage gives blast tuyere twice mid not to give wind, a blast tuyere criterion of both sides give sirocco.
(2) diagnose with the overhaul
Operate each key-press of air conditioning Control Panel, all can operate normally, dashboard does not have any calling the police information, but breakdown exists really. Use diagnostic appearance to undertake be diagnosticed oneself, inquire the breakdown information of system of automatic air conditioning, content is put in breakdown for LIN bus line. Examine the working data of system of automatic air conditioning, following:
Refrigeration agent pressure / Bar: 12.8
Signal of evaporator temperature sensor / ℃ : 7.4
Electric current of job of air conditioning compressor / A: 0.95
Signal of exterior temperature sensor / ℃ : 27.5
The temperature outside the car / ℃ : 26.5
Signal of sensor of the temperature inside the car / ℃ : 36.5
Cooling fluid temperature / ℃ : 95
Engine rotate speed / (R/min) : 750
Above data is done not have apparent unusual. Examine circuit figure, discover air conditioning system shares electromotor of 5 air door, they go up in LIN bus line with join of series connection means, LIN bus line controls module to come out from automatic air conditioning, ordinal allocate electromotor of air door electromotor, air door of left mixture air through electromotor of defrost air door, air, on the right side of electromotor of air door of loop of electromotor of mixture air air door, inside and outside. Use diagnostic appearance to undertake accommodative oneself study to air door electromotor, as a result diagnostic appearance shows cannot finish.
The power supply that checks automatic air conditioning to control module and the circuitry that take iron, normal. The plug part that controls module in this measures voltage of LIN bus line, for 13.5V, this voltage is exorbitant, abnormal. One by one unplugs the outlet that issues each air door electromotor undertakes checking, discovery should unplug when the outlet of electromotor of next air door of left mixture air, air conditioning system goes cool wind, two air door of appearance Taichun ministry also were opened. This shows electromotor of air door of left mixture air or the circuitry at the back of its to have trouble, still cannot decide breakdown is nodded. Continue to check, decide electromotor of air door of loop of inside and outside damages finally. Undertake changing handling, breakdown eliminates thoroughly.
(3) summary
This exemple breakdown reason is attaint of interior of electromotor of air door of loop of inside and outside, cause its between power source and LIN bus line short circuit. Power source voltage is 13.5V left and right sides, LIN line voltage is 11V left and right sides, became 13.5V when measuring voltage of LIN bus line so, system of automatic air conditioning enters protective state, cannot normal refrigeration, air door electromotor also cannot learn.
◆ ◆ runs quickly S350 air conditioning not refrigeration
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(1) breakdown symptom
Model of this car batholith is W221, configure M272 engine. During system of use air conditioning, the wind force of empty v a place with a draught was reduced suddenly, an a place with a draught of appearance stage both directions have a bit breeze, wind gap gives a bit in the center of wind also is done not have, operation wind force adjusts pushbutton, not effective.
(2) diagnose with the overhaul
Undertake affirming to breakdown symptom, discovery appears when breakdown when, adjust anyhow wind force, wind gap gives a bit in the center of wind also is done not have, the gives blast tuyere wind of both sides is very small, air-blower rotate speed did not change, and the wind force level that central indication screen shows can be pressed adjust have change.
Use diagnostic appearance to undertake be diagnosticed oneself to air conditioning system, two breakdown property is the breakdown information of current presence, one is air-blower adjuster (A32n1) communication breakdown; Another is LIN bus line is shut. The LIN bus line that looking is air conditioning system appears problem, measure the signal of LIN bus line with oscillograph then, the result is abnormal, be in the condition of right short circuit. Consult graph of circuit of air conditioning system, be informed this system to share 3 LIN bus line, the terminal that they part to control module outlet B with air conditioning 24, the terminal of plug D 3 with terminal 5 be linked together. The SAM before with the terminal of plug B 24 conjoint LIN bus line pass node Z68/3 to join air-blower adjuster is mixed controls module. The terminal with plug D the motor of 3 all air door that with terminal 5 conjoint LIN bus line use at controlling forehead area. In addition, the terminal of plug B the 24 terminal that control module interior and plug D in air conditioning 5 join are together.
Tear open next air conditioning to control module, oscillograph join is on the terminal of plug D, pull out next the terminal of plug B 24, right now oscillograph shows normal LIN signal is undee. Catch the terminal plug B 24 had received, next will before the terminal of the plug C5 of SAM control module 13 disconnect, right now LIN signal weaveform also is normal, and air conditioning system returns to normal.
Be before occurrence problem of SAM control module? What effect does the LIN bus line that dominates even the SAM before receiving module have again? The SAM before consulting controls the circuit of module to pursue, discovering a blast tuyere electromotor of system of hind air conditioning is pilot of module of control of the SAM before passing. Solid car undertakes metrical, affirming a blast tuyere electromotor of system of hind air conditioning also is by pilot of LIN bus line.
The overhaul so far, breakdown gradually Anacreontic, a blast tuyere electromotor that should be system of hind air conditioning or circuit has a problem. 4 when examine system of hind air conditioning give blast tuyere electromotor, when column of B of the side after what should tear open seat of the passenger before falling to fall is right gives blast tuyere electromotor, the outlet that discovers this electromotor was corroded, the reason is forehead evaporator drainpipe falls off, condenser water sheds seat lower part, cause the LIN line short circuit of this electromotor. Have this circuitry and plug clean processing, change on the right side of B column gives blast tuyere electromotor, test-drive, breakdown symptom disappears, overhaul job ends.
(3) summary
The component of connective of LIN bus line of air conditioning system is numerous, network structure is relatively complex, the overhaul rises difficulty is greater, need uses relevant data to analyse circuit trend, will search breakdown account through diagnose and measuring an outcome, remove trouble finally.
