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Clock spring short

Waynerd

NAXJA Forum User
A while back I had a code for TPS and swapped it out and still had problems. Finally read something about a short in the clock spring and pulled my horn fuse and TPS issue was resolved. Question I have, is there any way to isolate the sensor ground away from the bus or clockspring? I still don't fully understand the deal with the ground for the sensors running through the bus or how the ground can short to voltage supply in the clock spring. But it seems like I could just use an alternate grounding point for the sensors?
 
The 5 volt reference voltage used by the Cruise Control Switch Sense circuit and the TPS are shared inside the PCM.

Clock spring circuit to TPS circuit failure is not very common, and the short-term fix is simple, unplug the horn relay or unplug the clock spring. I don't see any benefit in messing around with what works 99.9% of the time, plus I have no idea about where or how one might go about this modification. I have a one or two spare clock springs from the junkyard, I think they were $ 15 each.
 
Ok. I'll try to keep it simple i guess. Just that I thought it could possibly do more damage than just make the sensors wack out. Wasn't sure if voltage through the ground could cause actual damage to the sensors or PCM.
 
I would assume that 12 volts is not good for the PCM, but the issue happens very rarely. I would worry more about blowing up stuff that I don't understand by trying to "fix" such a rare occurrence. If you installed a good quality clock spring, it should be good for another 15+ years.
 
I wonder if removing the horn switch pin from the clockspring connector would have the same effect without disabling the cruise switches?

Our shop just plays it safe and replaces the clockspring.
 
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