[Dieselfuelonly]

Had intermittent 4x4 issues last yr with the truck not engaging in 4x4 and causing the trasnfercase control unit under the passenger dash to buzz. Thought it was due to crappy fluid and didn't get to use it much last season.

I went to use it earlier in October and it did the same thing and would blink the 4x4 light (indicating a malfunction/code).

SELF-DIAGNOSTIC PROCEDURE (WITHOUT CONSULT-II) Description If the engine starts when there is something wrong with the 4WD system, the 4WD warning lamp turns ON or flickers in the combination meter. When the system functions properly, the warning lamp turns ON when the ignition switch is turned to “ON”, and it turns OFF after engine starts. To locate the cause of a problem, start the self-diagnosis function. The 4WD warning lamp in the combination meter will indicate the problem area by flickering according to the self-diagnostic results. As for the details of the 4WD warning lamp flickering patterns, refer to TF-36, "Diagnostic procedure" .
Diagnostic procedure
1. Warn up engine.
2. Turn ignition switch “ON” and “OFF” at least twice, and then turn ignition switch “OFF”.
3. Move A/T selector lever to “P” position.
4. Turn 4WD shift switch to “2WD” position.
5. Turn ignition switch “ON”. (Do not start engine.)
6. 4WD warning lamp ON. If 4WD warning lamp does not turn ON, refer to TF-70, "4WD Warning Lamp Does Not Turn ON" .
7. Move A/T selector lever to “R” position.
8. Turn 4WD shift switch to “2WD”, “4H” and “2WD” in order.
9. Move A/T selector lever to “P” position.
10. Turn 4WD shift switch to“4H”, “2WD” and “4H” in order.
11. Move A/T selector lever to “N” position.
12. Turn 4WD shift switch to“2WD” position.
13. Move A/T selector lever to “P” position.
14. Read the flickering of 4WD warning lamp. Refer to TF-36, "Judgement self-diagnosis" .

I would get back 13 and then 12.

I ended up doing the diagnostic procedures for 13 and landed at a faulty relay (transfer relay #2 ), I also removed the motor and confirmed it worked in both directions which it did and observed upon re-installation that it wasn't the easiest but I got it on to were there was no gap between the motor/transfer case. I ordered relays and upon my return from a little weekend away I installed them and was really hoping my lucky stars had aligned. Well no dice I had no 4x4 but no buzzing in the dash, the indicator by the odometer would flash front wheels and disappear and throw the 4x4 blinking light.

I didn't let it get to me took a breather and upon running the self diagnostic I kept getting no codes so I was thrown. I told my dad I would like to remove the motor and have him turn the switch to confirm operation at the motor and sure enough it worked as it should and I had a sense of relief or kind of. Next thing I wanted to do was put a tool in the transfercase and see how hard it was to turn the shift lever to engage the forks for 4x4 and it rolled real easy to our surprise, I didn't attempt to roll it the whole way into 4x4 because I had all 4 wheels on the ground still and wasn't trying to bind drive train.

I mentioned how difficult it was to seat the motor with the o-ring and suggested trying it w/o the o-ring and BAM 4x4 in and out. Whew one thing went my way. Replaced o-ring and there we go.

While I was under there also noticed my slip yoke will need to be pulled in welded as its leaking in the center and I also replaced a torn ground wire strap from the body to transfercase.

I note the manual DOES state to NOT reuse the original o-ring. I can't believe it was hindering me and glad it was something minimal to what it could of been.

Just something to note to those having 4x4 woes and keep in mind.

*Best of luck

 

[nanotech9]

This is the first and only post that provides any actual information about diagnosing this 4x4 problem (where the front wheel icons flash, go away, and the yellow 4WD light comes on solid).

Thanks for being thorough in the details posted. I need some help though. Where did you find the list of codes / descriptions once you got the number code from the flashing light?

I've been digging all over for info, but I think i'm searching the wrong terms

 

[Dieselfuelonly]

This is the first and only post that provides any actual information about diagnosing this 4x4 problem (where the front wheel icons flash, go away, and the yellow 4WD light comes on solid).

Thanks for being thorough in the details posted. I need some help though. Where did you find the list of codes / descriptions once you got the number code from the flashing light?

I've been digging all over for info, but I think i'm searching the wrong terms

Sorry for the late response as I am not as active on this forum or any for that matter.
I hope you have since solved your problem. I got the codes from the service manual for the Titan.
If you use google there is another site that hosts (or at least did, Im sure they still do) the full service manuals.

 

[Hodado]

I had this issue and it ended up being the ecu module and was replaced under recall even though i have a 2006 model.

 

[nanotech9]

well, I sorta solved my problem. Back in December a drunk driver slammed me off the highway at 70mph... spun out, cleared a 5' deep 20' wide ditch, crossed the service road, and stopped in the right-of-way on the far side of the service road.

Insurance totaled the truck... so, I never did chase down the problem.

I had already swapped the two smaller relays under the hood, but those didn't fix anything for me. I believe I was going to pull the actuator on the transfer case next and/or do a fluid change. I suspect it was very low.

 

[Dieselfuelonly]

well, I sorta solved my problem. Back in December a drunk driver slammed me off the highway at 70mph... spun out, cleared a 5' deep 20' wide ditch, crossed the service road, and stopped in the right-of-way on the far side of the service road.

Insurance totaled the truck... so, I never did chase down the problem.

I had already swapped the two smaller relays under the hood, but those didn't fix anything for me. I believe I was going to pull the actuator on the transfer case next and/or do a fluid change. I suspect it was very low.

Holy cow! I am sorry to hear about your misfortune but am glad that you are still with us!