![]() I don’t know the car’s repair history for its first 116,000 miles. It looked old enough to be original equipment, but hard to tell if it was just a factory alternate part thrown in during assembly, versus a really cheap aftermarket part. The old part has a much larger arc radius, and is pressed together with pins, not screwed together. I bought the genuine Volvo part from IPD (thanks for the discount!) but it did not match the part I took off the car. The cited web site with the step by step instructions was very helpful. ![]() That rowing trick worked, and I got the car home. ![]() Checking this board and others, I learned about the PNP switch, and the temp solution of “rowing” the gear shift rapidly. Worried that I was killing the tranny, I got off the turnpike right away and parked. Egad~!!!! Having never seen or heard of that warning before, I rolled to a stop in the toll takers parking lot, read the manual (“gear box failure” – whuh?), and did a restart. Wcorleyiii » The posts here on the PNP switch were a godsend! I got the dreaded yellow flashing arrow, and transmission power drop while whipping through a toll booth on the NJ Turnpike. Let us know how it goes by adding your comments! The PNP switch has to be aligned within 3mm of what it’s suppose to be for it to work at all so if you get it in and it doesn’t work, don’t assume that the switch is bad…it’s probably the alignment.” This is really not that hard though…much easier than trying to get an alignment tool. A bunch of stuff has to be moved out of the way and then once it’s in place you have to “adjust” or as they call it, align it. The PNP switch replacement is a bit of a pain. “I originally posted this as a reply to someone inquiring about how difficult replacing your own PNP switch was and then realized that we don’t have a write-up on this in our database, so I’ve copied my reply here as a fresh post. This write-up gives you an easy to follow step-by-step way to make sure the new PNP switch you install is properly aligned for your car! Comments are welcome in the thread. The alignment tool (apparently only sold by Volvo) is often times hard to acquire even from a dealer and really an unnecessary expense. The WIKA pressure switch PSD-30 is available either with PNP or NPN switching output.There is a good write-up on Volvospeed with pictures on how to replace your PNP Switch but what’s missing is how to align it once you get it in. ![]() In contrast, in North America, the country where the transistor was invented, relay outputs with potential-free contacts for AC 110 V loads are most widely used. In my experience, PNP switching outputs are used mainly in Europe, and NPN outputs almost exclusively in Asia. When a change in signal takes place by reaching a pressure value, the supply voltage (U+) is “switched on”, allowing current to flow from U+ through the load via the transistor and to GND. The load is connected to the switching output with U+ as the reference point. ![]() When a change in signal takes place by reaching a pressure value, the supply voltage (U+) is “switched through”, allowing current to flow from U+ through the transistor and through the load to GND. The load is connected to the switching output with GND as the reference point. This is why the load must be connected differently to the transistor outputs. In principle, both are bipolar transistors in which only the internal arrangement of the pn transitions differs. Here is a brief explanation how the two different outputs should be connected. Manufacturers of electronic pressure switches often offer both PNP and NPN switching outputs. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |