4lo indicator

[Roy2000]

Hello again.

Hope u can help me here;
on my 06 d40, when i drive in 2wd, there`s only black in the rear wheel, in the display. When i put it in 4H, the display blinks once, and there`s black in all wheels on the display.. But when i put it in 4LO, the display blinks once, and then the 4lo text blinks..

Should the 4LO text blinks, or light steady? Someone tells me that it should not blink, and someone says it blinks. It only the text so blinking, and all the wheels are black in the display.

The car is in low range, but i don`t know if it fully engaged. When i activate the diff lock, the ligth for lock, is blinking (yellow lamp).

The 4WD light is not lighting, som i doubt is some wrong with the 4wd system.

If the 4LO text should not blink, what can be wrong? It goes in and out of 2wd and 4wd/4wd lo easy, and i hear the "click" in the gearbox.

 

[Old.Tony]

I'm not sure what you're referring to when you say that you hear the click in the gearbox. When you move the selector from 4HI to 4LO the car will make a thump in the transfer case (that you can hear and feel).

It's not normal that the light flashes. You'll know if you are in 4LO, the car will feel like it's changed to a dramatically lower gear and will not move very fast at all in first.

If it's not actually moving into 4LO - and this has been an issue in the past - it may be the method of engaging 4LO that's at fault. It's happened to others before, and it just takes a little getting used to. The computer won't actually allow 4LO to be engaged unless the vehicle is stopped, your foot is on the brake (and both foot brake switches are engaged - see below) and the gearbox is in neutral. If you select 4LO without meeting those conditions, it will flash the 4LO text but will NOT engage 4LO.

There are TWO brake switches on some D40 models, one is to engage the tail lights and the other is to notify the cruise control module that you're on the brake. Don't ask me why, I know they could have used the same switch, but it wouldn't be the first time someone's just bolted on an extra widget to take care of something.

If your car is engaging 4LO, it's possible that it's either a sensor fault in the transfer case that's not detecting the full engagement of 4LO, or it's the servo not fully rotating. You can check the servo - from 2HI to 4LO it should rotate 270 degrees. If it's working, and you can manually rotate the input shaft 270 degrees, then it's probably one of the sensors - give the electrical connections a clean first, and if that doesn't fix things it'll be disassemble time.

 

[10navst]

Check your owners manual as a reference to see if its supposed to blink or not. From memory mine blinks the once as it engages then its a solid text.

 

[Roy2000]

I have checked the WAS, and the 4lo text, should be solid..
Can it be the sensors, when the gearbox go into low range, but not tells the controll unit that the low range is engaged?

 

[Old.Tony]

Sure can. There are sensors inside and they have failed in the past. There is one that says the planetary gears have realigned into low range - see p15 of TF.PDF in the manual. Scroll back to p14 for a picture.

 

[Roy2000]

I see.. I should get a fully diagnose of the 4wd system on monday, and check the sensors. I hope its just a easypeasy thing to fix

 

[morter]

I've got a 06 d40
I'm in 2wd yet the symbol is flashing 4lo, just started doing it out of nowhere. I've not used the 4wd in 6 months...

 

[Old.Tony]

Might be an ABS sensor on the way out? Does the car sound differently when cruising around a corner in one direction compared to the other? Possible failed wheel bearing - grease and particles enter the ABS ring creating an ABS fault causing the car to decide that 4LO is not usable.