If you knew me better you'd know why some of my friends and the DW sometimes call me the absent minded professor. I'm constantly forgetting little details like dropping the tag axle after tight turns. Thankfully the coach remembers to drop it at about 17 mph. Only problem is that at that speed, the Wabco ABS computer has set a error code because the tag axle's tires aren't turning at the same rate as their friends.
This throws an ABS error on the dash indicator light. I'm don't know if it has additional ramifications like disabling the ABS system in toto, but maybe? The standard treatment to clear the ABS error seems to be pulling over, shutting down the engine, restarting and carrying on. That's less than ideal for a bunch of reasons.
From what I can see, shutting down does nothing more than turning off the ignition key which in turn removes +12vdc from pin 7 of the Wabco computer (see attached). Since the Wabco computer is still powered up by x2, +12vdc feeds straight from the battery on pins 8 and 9, I reasoned that removal of +12vdc signal on pin 7 is simply the equivalent of CTRL-ALT-DEL for the Wabco computer.
Pin 7 from the Wabco is connected to wire #243 that terminates on our coach behind the front passenger kick panel on breaker #5. The load side of breaker #5 is double lugged with wire #243 to the Wabco and #243A to the cruise control disconnect(?). I disconnected wire #243 from beaker #5. I added a SPST NC MC (single pole, single throw, normally closed, momentary contact) toggle switch (https://smile.amazon.com/gp/product/B00XYE8GWS/ref=oh_aui_search_detailpage?ie=UTF8&psc=1) that I mounted in a blank switch position down by my left knee. One side of the switch goes to beaker #5 and the other to wire #243 that was previously connected to breaker #5.
IGN12VDC---->Breaker5---->>Switch---->>Wire#243---->>WABCOPin#7
When we exit our storage facility where the coach is kept, I have the tag axle raised because it's a tight turn. However, we are immediately on a 55mph highway with lots of traffic and even if I remember to lower the tag, it often isn't down with the wheels turning before the Wabco decides theres a problem and sets the ABS error condition. Now I just hold down the new ABS Reset switch for about 8 seconds and voila, the Wabco is reset and happy.
Enjoy.
Nope - just the wheel(s) which threw an error.
Great post!