4WD won't engage on electronic transfer box

Hello!

I searched the forum for a similar problem, but I could not find a relevant topic. So I am making a new one.


I noticed a big issue with my Jimny today. I can not engage 4WD. My Jimny has electronic transfer box (with buttons to change drive modes instead of the lever).

The car now runs in 2WD only. When I press the 4WD button (the middle button), the green 4WD indicator on the dash blinks just once, and that's it. It does not engage 4WD.
I tried to engage 4WD while stationery as well as while in motion. I also listened to the sounds emitting from the drivetrain during the 4WD activation process. Something "clunks" several times repeatedly (like a "klak klak klak" sound, but not loud), in approx 0,5 second intervals. Like it is trying to engage, but fails at the end.


Now, there is one thing which might be the cause. The last person who drove the car before I drove it today was my father yesterday. I asked him if he noticed anything unusual, and here is what he said:

When he embarked on his journey with the car, after around 50 meters he noticed that 4WD mode was on (I must have forgotten to disengage it when I had parked the car several days prior - I had used 4WD because it was snow on the roads that day).
So he pressed the 2WD button during motion to disengage. However, he was in the middle of a 90 degree turn on dry tarmac when he pressed that button. The car took a long time disengage 4WD (like 5-8 seconds), and the car managed to disengage 4WD only after he had completed the 90 degree turn. He heard a bit louder "clank" when it disengaged.

That is what he told me. He did not need and did not try to engage 4WD after that.

Based on his story, I suspect that something might have failed when he disengaged 4WD.



Does anybody have any ideas on what to look for, or has had a similar experience?
Can you give me some basic guidelines on what to check first?

I intend to drive the car to a qualified Suzuki service in my town if I have to. However, I would first like to try some basic diagnostics by myself or with a nearby mechanic in his garage, as Suzuki service is a bit expensive and they might charge me excessive service-hours if they disassemble the entire drivetrain because of "standard operating procedure" to check for every possible cause and fragment of the system.

I felt compelled to write a reply to conclude this thread, as it might be quite useful to someone else in the future.

I solved the problem a long time ago. It was so trivial it was annoying!


Here is the case:
There is a sensor in the electronic transfer box which, when you press 4WD button on the dashboard, apparently informs the ECU if the mechanics or pneumatics managed to shift into 4WD or not. There is a cable running from the underfloor to that sensor on the transfer box.

Well, the connector between the actual sensor and the cable is VERY flimsy, and it is also situated quite low on the transfer box, and it also "bulges" out of the transfer box. That is its factory position and mounting, which is VERY unfortunate design.

You see, a part of the cable got disconnected from the sensor connector on the transfer box (the cable has two wires, so one wire got disconnected). Therefore, the sensor could not send feedback info to the ECU during 4WD engagement process, so the ECU canceled the process every time.

I suppose that the wire was already partly damaged on the connection point with the sensor connector, and that the wind force was the thing which finished it off (I drove the car about 160 km/h on that day on the highway - I had never gone over 120 km/h before that).

When we temporarily connected the wire again, the transfer box worked perfectly. But the sensor connector has a very "closed" design, and it is IMPOSSIBLE to solder the wire back onto the connector. Very bad Suzuki design, if not even malicious! That sensor connector and the wire are one very weak element.

The wire goes about 10 mm into a tight hole into the connector plastic head, and therefore it is impossible to solder it because the connection is deep inside the connector.
What we did was this - we pushed the wire into the connector as far as we could, and while one of us held the wire in that position, the other guy glued the entire connector head and the cable with a hot glue gun. We then wrapped it all with several layers of insulating tape.

That is not the most secure solution, but works for now! I have driven for about 3000 km after that, no problem. I will get a replacement cable and sensor from a scrapped Jimny on a car junkyard. The new cable for the sensor costs bloody 80 EUR at my local Suzuki dealer, and it will not be an ounce less flimsy than the one which I have now.


P.S.: If you unscrew the connector from the sensor, all the oil from the transfer box will leak out.

I'm sorry no one responded to you. I would have directed you to the wiring under the car as although I have no experience with the electronic transfer box I have read of this same issue on here before on one occasion.

I wonder if a transfer box guard would assist in preventing this happening again if it's vulnerable.

Kirkynut

No problem and no worries - I understand that there are some cases when nobody has a good idea about the issue.

Luckily this issue was trivial to identify - a disconnected wire is easy to see on the transfer box.

I hope that my detailed explanation of the problem and the solution will help someone else in the future.

I definitely agree that some kind of transfer box underguard would be quite useful, at least in the part of the transfer box where this flimsy connector is.

There could not be more ironic situation when you get in a tricky situation in a forest in 2WD, to find out that you can not shift into 4WD because a flimsy wire got broken off, and no way to reattach it there.