TOD Help

Ok, awhile ago, the electrical engineer old guy (me) hooked up my son's battery backwards. It blew some fuses, which I replaced and all seemed to be ok with the world. However, we have noticed the TOD is now messed up. The TOD indicator lights seem normal but the back tires spin very easily, doesn't seem like the 4WD is working properly. Any ideas where to look? Does TOD have a fuse? Is it just a module replacement? Any other ideas? I am on the hook to fix this so am prepared to bend over and think of something else.

You could crawl under the passnger seat (just remove it) and check for output at the TOD module.

Look for a light-blue wire at pin 4 (check my gallery for details).
When the truck is idling, there should be (low) voltage present here. This is a 50 Hz PWM signal. The duty cycle increases as the need for torque increases. There are a number of different paths to ground used by the TOD module, so I don't believe that your problem is here.

If any of your vehicle speed sensors went, a CHECK light would have come on your TOD display.

maybe try putting all 4 tires up off the ground with jack stands and try accelerating (carefully). Or find a beach and play in the sand a bit.

Ok, will check waveform, but is there a TOD master module somewhere? My guess is I fried the module, or if I am lucky only a part of it.

Look in my gallery. The TOD control module is located under the passenger seat.