D40 4wd Light appears when fails to engage

[D40NAVY]

Hey, I've had the 4WD working for quite some time since I fixed it before. But the other weekend I was travelling on the beach when I stuck it in 4Lovand went through some soft sand the 4WD light appeared but was stuck in 4LO. When I turned off the vehicle it come back good to show the little image bottom under the revs. But when I got to select 4HI it would flash for about 3 seconds and show 4WD light and is still doing so......

I have replaced the transfer case switches about 5 months ago ( haven't cleaned them yet ), I have replaced the front ABS sensors they cost me 200 a pop and I've changed the oils in case, front and rear Diffs.

I don't want to go to nissan cause its an 2005 model and will cost me an arm and a leg, if there's any other way that'll be awesome

 

[Austinmurray]

Hey mate had some dramas with mine as well. Have you got any ABS lights coming up on the dash?

 

[D40NAVY]

Narh bro, I no ABS light, it did before and I changed the fronts over and it fixed it. Now something else is playing up I wish they didn't have sensors! And and old lock in hubs

 

[Old.Tony]

I'd look at the electrical connections to the transfer case, remove and replace them a few times each to give them a bit of a clean and see how it goes. Could also be a transfer relay (there are two) in the IPDM/ER (the black box behind the battery).

 

[D40NAVY]

Thanks matey. Do you know what plug I'm looking at,? Picture maybe

 

[D40NAVY]

Hey tony.. I don't have a relay that says IPDM/ER..

 

[kernels]

It helps with problems like these to have some idea about what is supposed to happen and how it actually works.

In old school 4wds you have a mechanical lever that selects 2wd/4wd/4wd low, on our utes this lever has been replaced by 2 electric motors and a few sensors.

When you go from 2wd to 4wd one of the motors engages a gear transfers power inside the transfer case to the front drive shaft, go back to 2wd and the motor disengages the same gear.

The other motor is to select high ratio or low ratio.

Now, normally I would say lie under the ute and have someone move the switch and have a listen if you can hear the motors running, but I'm not sure whether they will do their job with the engine not running ?

In your case it seems that the motor is not doing it's job, so I would look at fuses, relays and connectors that go between the switch on the dash and the motor on the transfer case.

I think the 4wd warning light is turning on because the sensors in the transfer case are actually working and telling the ECU that the gears did not engage / disengage as they were supposed to.

If all the fuses, relays and connectors are good, I would probably remove the actuators from the transfer case and have a look to see if they got any crap inside them or are possibly binding up for some reason.

 

[Old.Tony]

The IPDM/ER is the black box behind the battery. Just open it up and one by one, remove every item and reinsert it (this cleans the electrical contacts).

Once that's done, have someone engage 4WD while you listen to the relays in that box.

If the relays are working and 4WD is still not engaging, you'll have to pull the plugs from the transfer case - same deal. Listen while someone tries engaging 4WD - the servo should make some noise.

 

[kernels]

Hey oldTony, is there a single servo that does both 2wd/4wd and low/high range or are they two separate servos ?

 

[Old.Tony]

One relay and one servo handles the work. The servo turns 90 degrees (operating for 1 second) to engage the gear that drives the front shaft, and then turns a further 180 degrees (which takes 2 more seconds) to change gears in the planetary gearbox on the transfer case's input shaft.

If you remove the servo from the back of the transfer case you can stick a large flat screwdriver in and operate the mechanism manually. Maybe not the best thing to try while you're driving unless you've Flintstoned your car and can just reach under.