With a VDC, there is no jerking of the engine brought about by the switching on and off of the compressor clutch (as in FDC). It is possible to cheat an emissions test to conceal catalytic converter faults. When the AC doesnt require compressed refrigerant, the swashplate is in a neutral position where the piston stroke is zero. This Increases the swash plate angle and of course, the piston displacement. I think what happens is when people search for topics, old posts come up and people responded to it. 2) Is the oil in your compressor factory filled-in? Oxygen sensors behind the converter can be tricked. But after I replace the compressor and evacuate the system and add 134 it wont suck. Can anyone fill me in on how these new variable compressors work? If the pulley can be turned to the left, the limiter has triggered and the compressor must be replaced. With A/C off I get 29 mpg, with it on I have seen 25. ToyotaNation Forum is a community dedicated to all Toyota models. Externally controlled variable displacement compressors (ECVDC) have far better control of the piston displacement, and hence the temperature, compared to ICVDC. At idle cooling is just right. On each suction stroke of the pistons, a small volume of refrigerant is sucked into the compression chamber through the suction reed valve, which is then pumped out into the discharge chamber through the discharge reed valve on each compression stroke of the pistons. Externally triggered means that the stroke volume of the compressor is determined by a built-in control valve that is triggered by the air-conditioning control unit, depending on a wide variety of system parameters such as outside/desired temperature, high/low pressure, rotational speed, engine load. Can I directly supply a 12v from battery to the a/c compressor so that |I can add a 134? Is jump starting bad for your car? On the basis of these methods, it can be determined to what extent asignal change takes places through the control unit. This wastes fuel and makes it more difficult to modulate the vehicles interior temperature. However, resistance may vary due to higher underhood temperatures. Can one engine oil be used for all makes of vehicle? In earlier air conditioning systems, the compressor ran at full capacity whenever its cycling clutch was engaged. Oil with a black colour points to a defective compressor. HubPages is a registered trademark of The Arena Platform, Inc. Other product and company names shown may be trademarks of their respective owners. A differnent coolant is being used that does not have the high level of cooling ability of freon, so basically all air conditioners suck now, including my Lexus. This year's facelift of Mercedes-C-class Benz's sports sedan marks a major shift in design and engineering, but the car retains its winning combination of luxury and status at an accessible cost. However, a sensor thats stuck somewhere in its normal operating range could affect the operation of an a/c system. Increasing the duty cycle increases the pumping capacity. Start the vehicle, then adjust the a/c controls for maximum cooling and set the blower speed on High. And if you look at the compressor there is no non spinning parts like a clutch normally if the ac was off. And since the compressor's displacement is not maximum at normal condition, lesser engine power is needed. 8 shows how, in the case of the temperature setting High, the compressor is regulated downwards. The greyish discoloration points to metal abrasion. Which model, year, and options are you looking for? 4). This increases the pressure at the discharge chamber of the compressor, while reducing the pressure at the suction chamber. 2022 The Arena Media Brands, LLC and respective content providers on this website. This can lead to malfunctions or to failure of the system. This will answer the question Is the system working properly or is there a problem? 4 0 obj As the name implies, a clutchless AC compressor doesnt have a clutch to engage and disengage the compressor shaft from the drive belt pulley. This should help gas mileage a lot.. << /Length 5 0 R /Filter /FlateDecode >> ik |5AiO= =ah68^7uR:m6mX[PY`F_6D(4qLkD{oEpW FE:{t-XU{y>Hym^l3hk,PA 5O. Even a very small leak will cause the gauge to continually rise. Answer: If your new variable displacement compressor has a clutch (internally-controlled type), then go ahead. In the case of the lowest temperature setting ( Lo ) a square wave signal with a duty factor of approximately 75% (Fig. This makes the clutch entirely unnecessary in ECVDC, as shown in Fig. 9 was recorded in Econ operation (compressor off) and shows no signal. In other words the compressor is always 'on' but backs off 'compressing' unless its needed. If the cabin interior temperature gets cold enough, the system may start dropping off the control signal to the compressor. For some years, so-called clutchless, externally triggered, variable compressors have been used (Fig. This increases the resultant force on the piston head (F1 minus F2), which in effect increases the swash plate angle and the piston displacement. For example, The normal ECV resistance for this Hyundai variable displacement compressor should be 10.1 ~ 11.1 when the ambient temperature is 77F. The bellows of the displacement control valve (DCV) is at expanded condition, closing the low side port while opening the high side port. deleted using diagnosis equipment. It acts as a vibration damper and also protects the compressor or the other driven units from overload or damage. It may add to the cost of the service, but will help prevent comebacks. 2) is located in the compressor and receives its pulse-width modulated signals (PWM) from the air-conditioning control unit. Over the distance of thearea -B-, the current to the control valvefrom the control unit is regulated . To check the clutch, remove the drive belt tension.

The larger the displacement, the harder it is to turn the compressor shaft and the more engine power is needed. Catastrophic compressor failure may result. Instead, the drive belt turns the compressor shaft all the time.

Since the low-side port of the displacement control valve (DCV) is open at this stage, the same reduced pressure is present at the control chamber. Clutchless compressors also have a safety valve (Fig. In yet a third design, a sensor detects the flow rate of the refrigerant and the HVAC head uses that data to alter the swashplate angle. A compressor equipped with a clutch stands a better chance of survival because a low-pressure switch would signal the PCM to disengage the clutch. Bu the car is corolla 2010. The drive plate consists of a rubber element and forms the connection between the pulley and the compressor shaft. It is funny how everything is relative to the person driving.

Cool Automotive Products and Tool Recommendations, Read AUTO REPAIR ARTICLES sorted by topic, Car AC cold on one side, warm on the other, My opinion of the FortNine Youtube Fuel Stabilizer Test, My opinion on Project Farms Fuel Stabilizer Testing Video, Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN. I was forced to live full time in an RV to survive. Discover the causes behind the most common problems with your vehicle's lighting systems using this quick guide. For a better experience, please enable JavaScript in your browser before proceeding. Was driving in 90 to 100 weather and I think it works great. For a better experience, please enable JavaScript in your browser before proceeding. You hate the feeling you get in your gut if you discover a dent on your bumper, a scratch on your bonnet, or rust and peeling paint on the body of your vehicle. JavaScript is disabled. As a safety feature, the compressor features a plastic shear pin or hard rubber clutch plate (similar to a harmonic balancer) to drive the compressor shaft. 1a shows an ICVDC and Fig. Content on toyotanation.com is generated by its users. If theres sufficient pressure to run the system, check the signals to the compressor. components of the air-conditioning systemfrom excessive pressure. This is because the pressure switch shuts off the power supply to the compressor clutch preventing it from engaging. This increases further the pressure at the discharge chamber and decreases the pressure at the suction chamber. In order to check whether the limiter has triggered, the compressor shaft must be held using a suitable tool (Fig. As the compressor continues to run at maximum capacity (displacement), the cabin temperature will continue to decrease until the desired temperature is reached. The important thing to note is that the control unit registered the rapid change in throttle opening and responded by reducing the compressor output. This wobbling action causes the pistons to move back and forth at a short stroke. If the compressor should lock up for example, the transmission forces between the pulley and the drive plate increase considerably in the area of the rubber element. The displacement will increase only when there is a demand for it, like when the door is opened, but will return to its stable condition once the temperature is stabilized. Comma periodically issues Tech Talk training, When cooling system problems arise, determining the difference between a symptom and a cause can, Installation of certain oil filter elements can feel tight in comparison to alternative filter element. compressor 2mm 3mm 8mm 40mm clutch coils supply china ac categories A round thing next to the pulley or an end plate. Question: Is it ok to drive a variable compressor before its charged? Corolla 10th Gen/2nd Gen Matrix (2009-2013), The Fora platform includes forum software by XenForo, Camry 3rd and 4th Gen '92-'01, Solara '99-'03, Camry 5th and 6th Gen '02-'11, Solara '04-'08, VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada, toyotanation.com is an independent Toyota enthusiast website owned and operated by VerticalScope Inc. But it happen after I replace the compressor. The only way to modulate the pressure produced by the compressor was to disengage the clutch and allow the compressor to rest for a while. Refer to the shop manual for acceptable readings. If the pulley spins but the center bolt does not, the torque limiter slip clutch has sheared due to internal binding and the compressor must be replaced. In relation to this, the oscilloscope should be set to 5 V/divand 0.5 ms/div. Privacy policy | If more cooling is needed, the ECU increases the duty cycle of the PWM signal. There are two basic designs. To diagnose a no cooling or low cooling condition, youll need a shop manual. Sounds like maybe one of the AC pressure switches isn't working. Come discuss the Camry, Tacoma, Highlander, 4Runner, Rav4 and more! Note the wiring harness of the solenoid actuator (Fig. For this reason, all components of the system should always be included when troubleshooting. MEDIA | The variable displacement a/c compressor is one example of this increased complexity. Victor is a businessman, engineer, and teacher. That's an almost 14% drop my friends, horrible! Clutchless means that the compressor no longer has an electromagnetic clutch.

As stated previously, direct-drive compressors are constantly driven by the engine. The variable displacement a/c compressor addresses some of these shortcomings by changing the way the a/c system operates. It depends on the vehicle brand and compressor model. I think my AC works great. Provided that the compressor can be turned easily, the pulley and the rubber element can be replaced. Noise development. 2007 This channels the high pressure refrigerant to the control chamber. Your manifold gauge pressures would also be affected. Inrelation to this, there is the separate technical information. The end plate won't rotate only the pulley. To check for leaks around the Schrader valves, I use an inches of water (in.-H2O) pressure gauge connected to a hard-plastic hose. Thanks for the tip ! Rav 4 World is the internet's largest Toyota Rav4 SUV and EV online forum community. the displacement control valve prematurely closes the low side port, at the same time opening the high side port as the engine is revved up. 3. Some systems will display the compressor voltage/amperage applied on a scan tool. Again and again, complaints about compressors are hastily filed in connection with noises and other problems of air- conditioning systems. Even after sitting in the sun and getting in the car at 3:30 PM I hit the auto button, put down the windows for 2 minutes, close it up and minutes later it's comfortable. Manually rotate the direct-drive clutch and feel for a slight resistance or drag. The technical information Compressor damage provides information about different types of compressor damage and their causes. This prevents damage to the belt or other units driven by the belt. In an ECVDC, actuation of the control valve is done by the engines ECU or by an external electronic module by means of a solenoid actuator. Looking at BBBind.com web site schematic the A/C amplifier controls the compressor solenoid. The drive plate and the rubber element can be replaced individually. However it CRUSHES mpg. 7) is shown. When the system is charged and the compressor is not running the pressure in all chambers of the compressor is the same. 3). In other versions, a mechanical device moves the swashplate to the desired angle. The acceptable range is (8 ECV Resistance 14 ). If the oil in the compressor has taken on a red colour, this may be attributable to much moisture. During normal operation, the center bolt at the front of the pulley will rotate at the same speed as the pulley. On some vehicles, the pulse-width on time may drop only to 10%. In this case, a readout of the fault memory must be taken and Unlike the old fixed displacement compressor (FDC), the variable displacement compressor (VDC) automatically varies its pumping capacity to meet air-conditioning demands. An incorrect quantity of refrigerant can also be responsible for various noises. depending on the compressor type, designeddifferently. Black Book, Diagnosing Variable Displacement Compressors. I a usually repair my car but this problem is too confusing for me. That dash gets mighty hot. Although, when it's real hot out and the sun is high, I wish that I didn't have a Sport with the dark interior. Suppose the cabin temperature has now dropped down to 45F.

Eautorepair.net redraws factory wiring diagrams in color and includes the component, splice and ground locations right in their diagrams. If you need to dig into your doors, dash or console, Alldatadiy.com is the better choice because Eautorepair.net doesnt any interior or exterior trim or body part removal. Here, ideally, the use of an oscilloscope is helpful. Also, when the vehicles inside temperature is cool enough, theres no need for the compressor to operate at full capacity, and its output can be reduced. This allows the pressure developed by the compressor to be applied gradually, rather than come on at full force. I'm with SeriousBlack on this. "thing next to the pulley" is a little unclear, can you be more specific? If the film of the valve is damaged, it can be assumed that the valve has triggered. Fig. Noises are caused not only bythe compressor, but also by its fastening, the drive, the expansion valve or the lines. For this, it is however essential to connect a load which corresponds to that of an electronic control valve to the control-unit side of the air-conditioning system. The same gauge is also used for evap testing. Was it worth it? Question: What is the feedback mechanism by which the cabin temperature is communicated to the Internally Controlled VD Compressor? The first type is a direct-drive compressor thats controlled by a pulse-width modulated voltage signal only. The control module has commanded the compressor to drop off the pressure. xZ6}WZffvwaL,2vt29ER-tY,U:,~oDa) Pf)J%olJ&Xx^ddoIA?etE6-OwRsIk[5|#LK'i^QoxKe[ A functional check by means of a PWM signal can also be carried out using a function generator (Fig. %PDF-1.3 When the compressor runs , the swash plate which rotate with the shaft wobbles a little. AC systems remove heat and moisture from a car's passenger compartment using refrigerants such as R-134a in a closed system. This will cause the high-side gauge pressure reading to drop as well. This generation of compressors is used by almost all vehicle manufacturers (Audi, BMW, Citroen, Seat, VW, Opel). Alldatadiy.com, on the other hand, uses the factory diagrams. But just to sure, turn off the ac switch. When servicing the system, replace the Schrader valves, if possible. They include wiring diagrams and technical service bulletins. I had a 1986 honda accord that had such cold air blowing out of its vents on a 90 degree day that you could see your breathe, of course that was freon, and it has been banned so those days of super cold air are over. 5). Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters. The second type is basically the same, but with the addition of a conventional electromagnetic clutch mounted on the compressor shaft. The pulley unit of the compressor consists, for example, of a drive plate and the actual pulley (drawing). I will break down the associated costs. My mechanic said that the input voltage of the clutchless compressor go up & down from 4v-13v. I tried to look at the dates but occasionally revivied zombie posts. This serves as the basis for being able to make a statement as to what extent the compressor still functions perfectly. The current which is fed from the control unit to the control valve, and which ultimately determines the power of the compressor, can be displayed as a measured-value block with the aid of diagnosis equipment. Thanks for your support.

Pricing: ---Eautorepair.net--- 1 month subscription $19.95 per vehicle 1-year subscription $29.95 per vehicle 4-year subscription $44.95 per vehicle ---Alldatadiy.com--- 1-year $29.95 subscription: additional vehicles $19/95 each 5-year $49.95 subscription: additional vehicles $34.95 each Which one should YOU choose? That doesnt mean the compressor is compressing refrigerant full-time though. 1b. To test the performance of the compressor's variable control solenoid, perform the following steps: 1. So you have to refer to the factory legends to learn the identification symbols and then refer back to circuit diagrams to find the splice and ground locations. A look back at Cars: Accelerating the Modern World - an exhibition at the V&A in 2019. during air-conditioning servicing and when replacing components. been triggered: In the case of the Audi A3 for example, at the lowest temperature setting, the maximum current that is fed from the control unit to the control valve is approximately 0.65 A. Diagnosing variable displacement compressors is basically the same as with the old-style compressors. In actual operation, when the air-conditioning system has stabilized and the desired temperature is reached, the piston displacement is neither maximum nor minimum. rav4world.com is not in any way affiliated with Toyota Motor Corporation. The new one the end plate rotate together with the pulley. :twisted: My A/C works great as well. And since the low-side port of the control valve is still open at this stage, the pressure at the control chamber is also reduced. The invention of the car had profound effects on culture, the landscape, and even fashion. However, in relation to this, the power is regulated down to a few percent. The pulse width depends on the desired coolingperformance and the vehicle-electric-system voltage. This also applies to the blow temperature. In fact, some VDCs have no clutch at all. 1b shows an ECVDC. This is the first variable capacity compressor on a vehicle that I have seen too!

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