Mitsubishi Repair Problems? Ask a Mechanic for Answers ASAP
When you grounded pin 1 of the DLC connector was the code #22 outputted through the ABS light or through the C/D light? If the ABS, what behavior did the C/D light have when the pin was grounded?
Thanks.There are two issues at hand most likely. With regard to the front lights blinking, this is because the range switch on the transfer case isn't matching the position switch of the front axle. This is pretty much always either a vacuum issue (as you already suspected) or a failure of the free wheel clutch solenoid pack on the frame rail beneath the air filter.
It is possible that this failure could interfere with getting 4L to engage, but I would not really expect it.
What you need to do with regard to the flashing front lights if you have definitely verified zero vacuum leaks etc, would be to pull the solenoid pack and bench test it... you should see aorund 35 ohms each solenoid, but more importantly when drawing vacuum on either solenoid and energizing the solenoid with a battery and some wire, you should not be able to draw vacuum regardless of voltage or release vacuum regardless of voltage. Each one should be able to hold indefinitely and release instantly as voltage is applied/removed... most likely this will not be the case and the unit will require replacement. It is the #1 4WD problem we see on these trucks.With regard to the not getting 4L... again there could be relation but as many solenoids as I've seen on these it would be the first time I had seen/heard of this behavior. So I'm a bit pessimistic about that fixing both issues.Are you able to pull the transfer ecu and check the voltage outputs from the range switch to make sure it is actually seeing the request for 4L?
If you are hearing interaction then it is likely getting the signal then.
At this point I would want to address the front axle issue (lights flashing, vacuum/solenoid issue) and see if the symptoms change at that point.
No, I am not aware of any way to effectively shift the unit manually. If you had a burnt out motor or a high resistance situation due to internal seizing etc, you would throw a fault in the transfer ecu for it so I doubt there is anything to go on there.
Lets get the front wheel situation straightened out and see if the other issue resolves itself as well.