Navara 4WD warning light dilemma

Hi everyone,

I have recently purchased a 2012 Navara ST Spain built vehicle. Since owning it I have discovered that 4WD does not seem to engage. When switching to 4H it illuminates all wheels on the instrument cluster for a second or two then goes blank and the 4WD warning light comes on and stays on until which time I turn the vehicle off and then back on.

I have done basic research into suggested fault and a lot of people mention blinking warning lights. This is just solidly illuminated.

Can anyone offer suggestions? I have investigated the plugs on the transfer case and they all seem to be clean and intact. Pictures would be a huge help as I am relatively new to 4WD's.

Cheers,

Zack

I would suspect a solinoid failure or loose connection. Perhaps log on later, Tony often comments on this issue.

OBD2 scan tool may give you some information, could be a solenoid as mentioned above or sensor. Have you checked whether it actually is in 4wd when you flick it over ?

Gday guys. I have checked that it is not engaging 4WD. I will take it to a mechanic and get them to suss it out. Was just hoping that I could eliminate some possibilities before I resorted to paying someone.

Sounds like the wait sensor inside the transfer case. Not a common failure point but it's happened a couple of times. There's a sensor (switch) which detects that the gearbox has engaged or disengaged the drive to the front axle. If this switch fails, the servo starts its motion, the pawls slide into place and 4WD engages, but the switch never changes state so the car thinks something is wrong in the transfer case and alerts you by disengaging 4WD (the servo returns to normal position) and bringing on the 4WD light.

Hi Old.Tony. Thanks for your response. How would I identify the wait sensor?

The wait sensor (wait detection switch is its proper name) is under the box at the rear behind the large mating face and somewhat to the left of the axis of the front drive shaft.

I suppose you could check the transfer relays too - there's a black box in behind the battery (it's near the wiper washer filler) and 4 of the relays belong to the transfer case. There are two transfer shutoff relays and a shift low relay and a shift high relay. A failure in one of these could cause the error too.

Sounds like it would be a good idea to lie under the car with your face near the back of the transfer case and have someone inside the car change the switch from 2Hi to 4Hi and have a listen to the actuator.

If it's turning, then turns back, it points to the wait switch as Tony said.

If the actuator never makes a sound, then I would be looking at fuses, relays and connections.

I would be very surprised if it's a complex problem, more likely something quite simple.

Thanks guys I will have a look at the relays that Tony mentioned as I laid under the vehicle and had my partner flick the switch and no sounds or movement what so ever.

I did this with the car not actually started but the ignition turned on as mentioned in another thread. Is this correct?

No, just tried that on mine, looks like the car must be running for it to try and go to 4wd. Definitely makes it a lot harder to try and hear if something is happening with the actuator.

Might be worth unbolting the actuator in that case, and physically looking at it when you try to change mode.

I hate to sound like a dumbass but where would the actuator be situated? Are you able to show me a picture of it?

The servo is a large black unit on the back of the transfer case. It has a square (with rounded corners) shape and a plug that goes in the side of it.

So Tony. I assume this is the black box you are referring to. Which relays are you referring to?

Hmm, wrong box. The manual has this snippet in it showing the placement of the relays:

Thanks Tony. I have a feeling that's on the other side. I'll have a look ASAP.

Just had a play with moving the relays around. It seems that the warning light is now gone. I haven't tested the 4WD capabilities yet. However when switching to 4LO is that symbol meant to keep flashing?

The symbol flashes until the transfer case can engage 4LO. You should hear - and feel - a nice solid thump from under the car when yours engages.

Could it keep flashing and not engage if one of the relays is still buggered? As I said I just moved them around so potentially the one that's rooted could be the one that now engages the 4LO function.

Sure. The wait sensor is for the locking pawls that engage the front drive shaft, the 4LO is detected by a separate switch.