Central Warning System repair - Write-up is available!
07-05-2006, 07:25 PM
#16
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Thank you Tom
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
07-06-2006, 07:14 AM
#20
Rennlist Member
Excellent procedure Tom: you've motivated me to go back on my cruise control module ... it did not respond to a reflow of the primary solder joints, so now on to the thousand small joints & components ...
07-06-2006, 09:31 AM
#21
Rennlist Member
What symptons would prompt a CWS repair?
All my warning lamps stay illuminated when car is running. Could my CWS be faulty? I repalced my electrical ignition switch and no change.
Thanks
All my warning lamps stay illuminated when car is running. Could my CWS be faulty? I repalced my electrical ignition switch and no change.
Thanks
07-06-2006, 01:56 PM
#22
Rennlist Member
Thread Starter
I am glad eveyone is finding this useful.
Mike - My initial failure symptoms were no warning lamps at all! After re-flowing some solder joints all my warning light were on when the car was started, which sounds like the symptoms you are experiencing. With the battery strap off, try unpluging the black connector to the CWS unit. Reconnect the battery, all your warning lamps should be out and the car should start and run. If so, then the CWS is likely your problem.
Garth - interesting you mention the cruise control. Mine is working but not holding speed so I will dig into it next. Then the fuel injection controller.
BTW - If anyone has CWS, cruise control or fuel injection controllers that are NON-functional. I would be very interested in them to create troubleshooting information (procedures, schematics, etc) so I don't have to use functional units and possibly damage them. These would not be fixed - just used to create troubleshooting information.
Mike - My initial failure symptoms were no warning lamps at all! After re-flowing some solder joints all my warning light were on when the car was started, which sounds like the symptoms you are experiencing. With the battery strap off, try unpluging the black connector to the CWS unit. Reconnect the battery, all your warning lamps should be out and the car should start and run. If so, then the CWS is likely your problem.
Garth - interesting you mention the cruise control. Mine is working but not holding speed so I will dig into it next. Then the fuel injection controller.
BTW - If anyone has CWS, cruise control or fuel injection controllers that are NON-functional. I would be very interested in them to create troubleshooting information (procedures, schematics, etc) so I don't have to use functional units and possibly damage them. These would not be fixed - just used to create troubleshooting information.
07-07-2006, 12:11 AM
#23
Rennlist Member
Thanks Tom, just replaced my CWS unit with a used one and everything works fine now!
I did open my CWS , noticed the long eprom( no glue) pulled and pushed it, was not up to reflowing solder, but I have the old unit if your interested.
I did open my CWS , noticed the long eprom( no glue) pulled and pushed it, was not up to reflowing solder, but I have the old unit if your interested.
Originally Posted by Tom928
I am glad eveyone is finding this useful.
Mike - My initial failure symptoms were no warning lamps at all! After re-flowing some solder joints all my warning light were on when the car was started, which sounds like the symptoms you are experiencing. With the battery strap off, try unpluging the black connector to the CWS unit. Reconnect the battery, all your warning lamps should be out and the car should start and run. If so, then the CWS is likely your problem.
Garth - interesting you mention the cruise control. Mine is working but not holding speed so I will dig into it next. Then the fuel injection controller.
BTW - If anyone has CWS, cruise control or fuel injection controllers that are NON-functional. I would be very interested in them to create troubleshooting information (procedures, schematics, etc) so I don't have to use functional units and possibly damage them. These would not be fixed - just used to create troubleshooting information.
Mike - My initial failure symptoms were no warning lamps at all! After re-flowing some solder joints all my warning light were on when the car was started, which sounds like the symptoms you are experiencing. With the battery strap off, try unpluging the black connector to the CWS unit. Reconnect the battery, all your warning lamps should be out and the car should start and run. If so, then the CWS is likely your problem.
Garth - interesting you mention the cruise control. Mine is working but not holding speed so I will dig into it next. Then the fuel injection controller.
BTW - If anyone has CWS, cruise control or fuel injection controllers that are NON-functional. I would be very interested in them to create troubleshooting information (procedures, schematics, etc) so I don't have to use functional units and possibly damage them. These would not be fixed - just used to create troubleshooting information.
06-01-2009, 11:36 PM
#25
Burning Brakes
Awesome,
Followed the procedure and now mine is fixed!!
BTW - Symptoms
Warning lights were working but completely erratic. Sometimes on sometimes off, different combo's, steady flashing......................you name it?
Also, my fuel gage was very erratic too and now it is completely cured. I wouldn't have guessed that the fuel level needle went through the box as well but I guess it does since after I took the box out, the fuel gage did not work at all.
Great writeup
You've saved me a bunch of searching and probably money as well!!
Followed the procedure and now mine is fixed!!
BTW - Symptoms
Warning lights were working but completely erratic. Sometimes on sometimes off, different combo's, steady flashing......................you name it?
Also, my fuel gage was very erratic too and now it is completely cured. I wouldn't have guessed that the fuel level needle went through the box as well but I guess it does since after I took the box out, the fuel gage did not work at all.
Great writeup
You've saved me a bunch of searching and probably money as well!!
06-02-2009, 01:00 AM
#27
Team Owner
Tom thats a great job, thanks for taking the time to put this together
06-02-2009, 02:41 AM
#28
Rennlist Member
Nice writeup! The '78 version doesn't have the big socketed IC, but there's nothing wrong with getting in there and looking for burned components, re-soldering the connections, etc.
06-02-2009, 08:27 AM
#30
Rennlist Member
I don't know how I missed this excellent writeup the first time around but I'm glad this thread resurfaced. One of my first posts here was about warning lights: mine "blink" on and then go off so fast I can't tell what's happening! The CWU was suggested as the culprit, but I just put this on the back burner- back to the head of the queue now, I'll report if this fixes the issue. Thanks, Tom!