1 Answer

P1686. The engine controller received an invalid key from the SKIM.

It receives information whether the key is in the ignition, key hole on passenger or back will not matter.

Make sure you can open the vehicle with the key or keep a window down.

Try this:

1. Disconnect the battery and put terminal together(this drains capacitor in PCM and BCM). Leave disconnected for 5 minutes.

2. Connect the battery.

3. Put key in ignition and turn to ACC(without cranking it) for 1 minute. Then try to start it.

By doing this procedure, disconnection of the battery and reinserting it the the ignition, it forces the BCM to relearn its data from the PROM.

Like any computer a reboot is all it takes or restart clears the confusion on computers.

http://www.fixya.com/cars/t9041318-1999_jeep_showing_code_p1686