93ZJ - 4 wheel drive switch + bad coolant sersor

You have the Quadratrack transfer case. Problem is the sensor is internal to the xfr case. I'd remove/clean/reinstall the connector first. It's an oval 4pin located on the transfer case. not too easy to get at though.

On the bright side, the 4wd and coolant sensor errors are not critical providing the range selection is correct, the fluid has been changed regularly, and you keep an eye on the overflow bottle so the level is between fill and add with the engine at operating temp.

As for 2, clean the contacts on the sensor that is on the coolant reservoir, it's likely a bit corroded.

If it is the same sensor used on the WJ... When I got the error I just disassembled and cleaned it really well in the basement and reinstalled it. Been working fine for almost 2 years now.

Sensor in the WJ fits into the expansion tank.

Hi Everyone,

Thank you for your input.

I did a throughout car wash last weekend. I also cleaned the connectors.

The error messages did not re-appear ... for the last short while. I still keep my fingers crossed.

Thanks again

Paul

My experience on the 93 is that most problems can be solved by cleaning connectors. Especially the ABS light coming on when you hit bumps. That's caused by the crappy location they chose for the ABS computer. The connector accumulates road debris and rain from the hood drain. Thankfully it's easy to clean.

Don't forget to keep the Idle Air Passage in the trottle body clean. That causes rough idle.