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The pulse width modulated duty cycle signal


Several years ago, when vehicles using these compressors were just starting to show up at shops for service with some regularity, we were searching to find some detailed information about their behavior to use in clinics.  There was not a lot of it available, so we borrowed several vehicles and did some videos.  The following are some clinic slides produced from one of those videos.
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Diagnosing electronically controlled compressors

November 30, 2021

When preparing to conduct diagnostics on a system using an electronically controlled variable displacement compressor, the diagnostic process needs to focus on four areas.
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Exploring electronically controlled variable displacement compressors

November 23, 2021

Electronically controlled variable displacement compressors (ECVDs) have been in use now for over 15 years.  然而, there are a lot of technicians in the field who have very little knowledge about them and their operation.
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EPA releases Automotive Trends Report


Vehicle enthusiasts may want to check out the U.S. EPA's newly released Automotive Trends Report.
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Disassembly and inspection of a seized compressor


MACS Tim Iezzi takes apart a problem compressor in this step-by-step video.
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You can get Tesla repair information


Find out how to use Tesla software for aftermarket repair
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Troubleshooting the “what ifs” in a mobile A/C repair


High side:  Likely somewhere around 130 psi (at an idle) & 140 psi at 1500 rpm.  为什么? With only a 35% charge in the system, the compressor isn't going to be producing a lot of pressure.
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What do you know about the fixed displacement piston compressor?


What do you know about the fixed displacement piston compressor? 
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At this time of year, I often end up with an earworm in my head from a Canadian rock band … Summer’s going fast, the nights are growing colder. Then it’s the line everyone knows from something more mainstream … 冬天即将来临. It’s early September, and the leaves on some trees are already starting to change. 冬天即将来临.
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J1587/J1708 and J1939 data line diagnostics


Modern heavy-duty equipment is basically comprised of computers with operating units attached. 简而言之, it is a multiplexing system that replaces traditional power distribution devices with ECUs that communicate electronically over the vehicle datalink.
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