Centre diff lock would not disengage (150 3.0td)

[Spark45 Junior Member Find all posts View Profile Close Spark45]

Hi Guys,

Had a bit of a blip on the weekend.

I've had my 2010 150 TD about 2 months, taken her offroad and on some moderate 4wd tracks 6-7 times to date, low range and centre diff lock going on / off no problems every time.

On the weekend drove for about 10 minutes up a gravel/dirt logging road with diff on, camped the night, drove back down.

Problem is when I was back near the pavement at the bottom the diff lock would not go off. I'd press the button and the light would just flash and flash and flash.

Turned it back on, light stayed on solid.

Turned it on/off a few times, no change.

Drove forward a bit, back a bit. Still no luck.

Car on/of then tried again, no luck.

Ended up putting it in low range, driving forward, turning both off, then light stayed off.

Hadn't used low range the whole trip so not sure why that seemed to be the kicker.

Can anyone enlighten me? Bit worried about putting it back on now for fear of being hours away from town and not being able to turn it off.

[Fred63 Advanced Member Find all posts View Profile Close Fred63]

i had this happen a couple of times.
Driving forward and back about 10mtrs then is disengaged.
There is another thread on here about using the center diff lock.
There are differing opinions personally i do not use it unless it think i might get stuck.
i would not use it on a dirt / gravel track

[slimf Senior Member Find all posts View Profile Close slimf]

Happens all the time.. Sometimes takes a few seconds and sometimes it's a bit tougher.. Just go back and forth.. Etc


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[MYT150 Member Find all posts View Profile Close MYT150]

You don't say if it is auto or manual. But from memory in the auto you need to stop and have your foot on the brake to get it to unlock, and I think it also needs to be in park or neutral as well.

[Nik83 Member Find all posts View Profile Close Nik83]

Ive seen similar but i think it's come down to torque in the diff / xfer case being present... I've found the following works: neutral, centre diff off, wait a few seconds, shifter in drive, slowly move forward.

[AK7 Senior Member Find all posts View Profile Close AK7]

You can turn it on and off on the fly. If memory serves me correctly, up to 80KM/h. It's stated in the manual. The car pretty much needs to be rolling for it to engage/disengage. I had this issue a while back, but after re-reading the manual, I only ever engage/disengage it when I'm moving.

[Spark45 Junior Member Find all posts View Profile Close Spark45]

You don't say if it is auto or manual. But from memory in the auto you need to stop and have your foot on the brake to get it to unlock, and I think it also needs to be in park or neutral as well.

My bad, it's a manual.

All done at complete stop, out of gear (not in gear with foot on clutch), with foot on break.

Same as always, just this time it wouldn't click.

[Spark45 Junior Member Find all posts View Profile Close Spark45]

You can turn it on and off on the fly. If memory serves me correctly, up to 80KM/h. It's stated in the manual. The car pretty much needs to be rolling for it to engage/disengage. I had this issue a while back, but after re-reading the manual, I only ever engage/disengage it when I'm moving.

Well that's more confusing because every time I've turned it on/off previously was dead standstill.

[AK7 Senior Member Find all posts View Profile Close AK7]

Well that's more confusing because every time I've turned it on/off previously was dead standstill.

As I mentioned earlier, the details are in the user manual. It only ever fails to disengage if you're stationary.

[Brett1979 Avid PP Poster! Find all posts View Profile Close Brett1979]

AK7 raised a good point. Change it from lock to unlock while the car is actually moving and the centre diff lock light should turn off in timely fashion. When the car is stationary and you shift it to unlock, then usually you'll need to drive forwards or backwards for 10 meters to get it comply. But there are times when you change it while stationary that the light may not go out for a few minutes of driving. I've never changed mine while moving as I don't ever use the high range diff lock as I find it rather useless (auto transmission). I either use standard high range unlocked or low range locked and skip high locked altogether.

[MYT150 Member Find all posts View Profile Close MYT150]

Ok so I have reread the Toyota offroad driving manual, I knew I had to stop for something, which is also when I usually engage the centre diff lock, although according to Toyota I shouldn't unless I am stuck.

Shifting from H4 to L4
1) Stop the vehicle completely with brake pedal held down.
2) Automatic transmission: - Shift the shift lever to N.
Manual transmission: - Depress and hold the clutch pedal.
3) Vehicles without Multi-terrain Select: - Push and turn the four-wheel drive control switch clockwise.
Vehicles with Multi-terrain Select: - Push and shift the four-wheel drive control switch to L4.
Maintain this condition until the low speed four-wheel drive indicator turns on.

Shifting from L4 to H4
1) Stop the vehicle completely with brake pedal held down.
2) Automatic transmission: - Shift the shift lever to N.
Manual transmission: - Depress and hold the clutch pedal.
3) Vehicles without Multi-terrain Select: - Turn the four-wheel drive control switch counterclockwise.
Vehicles with Multi-terrain Select: - Shift the four-wheel drive control switch to H4.
Maintain this condition until the low speed four-wheel drive indicator turns off.

When the H4 position and L4 position can be switched with the four-wheel drive control switch

• The engine switch is turned to IGNITION ON mode.
• The shift lever is in the N position (automatic transmission).
• The clutch pedal is depressed (manual transmission).
• The vehicle is stopped completely.


When the center differential lock/unlock switch can be operated
The engine switch is turned to IGNITION ON mode.

The center differential lock indicator and indicator in the differential lock/unlock display
The indicators blink while locking/unlocking the center differential.
If the indicators blink and the buzzer sounds when the center differential is
locked, stop the vehicle completely and operate the switch again.
If the indicators continue to blink even if doing so, have the vehicle inspected
by your Toyota dealer as soon as possible. There may be a trouble in the
four-wheel drive system.

Locking/unlocking the center differential
If the operation is not completed, the center differential lock indicator and
indicator in the differential lock/unlock display blink. If the indicators do not
turn off when unlocking the center differential, drive straight ahead while
accelerating or decelerating, or drive in reverse.
Avoid turning suddenly while the center differential is locked. If you do turn
suddenly, the difference in turning speeds between the front and rear
wheels may have a similar effect to braking, thus making driving difficult.

[AK7 Senior Member Find all posts View Profile Close AK7]

Ok so I have reread the Toyota offroad driving manual, I knew I had to stop for something, which is also when I usually engage the centre diff lock, although according to Toyota I shouldn't unless I am stuck.

"Use when the vehicle is stuck or when traction is otherwise necessary.". In other words, use your own judgement when to use it. I'd rather engage it when necessary to help avoid getting stuck.

Sorry I didn't hunt for the manual myself. Big day yesterday. There is no inferrence that the car must be stopped to operate the centre diff. My comment earlier of "up to 80KM/h" is clearly not accurate but I'm sure I've read a figure somewhere. I tend to operate mine at idle speeds, when approaching or departing an obstacle. Doing it that way, I never have issues engaging/disengaging it. The rear diff is a maximum of 8KM/h and use in L4 only.

The instructions are:

Center differential lock (→P. 123)
Use when the vehicle is stuck or when traction is otherwise necessary.
The center differential lock can be used by pressing the center differential lock/unlock switch regardless of the transfer position.
Make sure that the center differential is unlocked when not needed.

Center differential lock/unlock switch
Lock the center differential when your vehicle’s wheels get stuck in a
ditch or when driving on a slippery or bumpy surface.

The center differential lock indicator and indicator in the differential lock/unlock display will come on.
To unlock the center differential, push the switch again.
Unlock the center differential after the wheels have been freed, or after moving to a flat, non-slippery surface

When the center differential lock/unlock switch can be operated

• The engine switch is turned to IGNITION ON mode.

The center differential lock indicator and indicator in the differential lock/unlock display

• The indicators blink while locking/unlocking the center differential.
• If the indicators blink and the buzzer sounds when the center differential is
  locked, stop the vehicle completely and operate the switch again.

If the indicators continue to blink even if doing so, have the vehicle inspected
by your Toyota dealer as soon as possible. There may be a trouble in the
four-wheel drive system.

Locking/unlocking the center differential

• If the operation is not completed, the center differential lock indicator and
  indicator in the differential lock/unlock display blink. If the indicators do not
  turn off when unlocking the center differential, drive straight ahead while
  accelerating or decelerating, or drive in reverse.
• Avoid turning suddenly while the center differential is locked. If you do turn
  suddenly, the difference in turning speeds between the front and rear
  wheels may have a similar effect to braking, thus making driving difficult.

CAUTION

• Do not operate the center differential lock/unlock when the vehicle is turn-
  ing or when its wheels are spinning freely off the ground.

NOTICE
To prevent damage to the center differential

• For normal driving on dry and hard surface roads, unlock the center differ-
  ential.
• Unlock the center differential after the wheels are out of the ditch or off the
  slippery or bumpy surface

https://toyotamanuals.com.au/docs/la...ug-13-current/

[saftgt Junior Member Find all posts View Profile Close saftgt]

My 2010 150 D Auto...... gear in N....foot on break.... select diff lock..or 4x4....foot off break.... in D .....and away I go'

on another point....i was driving to work the other day and both 4x4 and dif lock lights started flashing. stopped... tried that above proceedure....nothing....no 4x4 or did lock..... drove slowly back home...... read manual.... check everything a IT person could think of. still no luck. Then disconnected the battery for 5 minutes and all okay. CRT.... Alt.... delete...... I was relieved

[brundah01 Junior Member Find all posts View Profile Close brundah01]

All the specific unlock procedures have been discussed relevant to the modern drive lines. But the fundamental cause may not have been expressed clearly.

Normally with good 4x4 driving practices off road in difficult conditions, driver will engage differential lock/s early and at low speed! (refer specific manuals).

Most center lock-up problems occur when the vehicle returns to a solid surface, after individual wheel/s traction has been lost or, after hard cornering!

"Centre Diff will not disengage" on return to solid surface, usually occurs when a condition called "drive line wind-up" is present!

For many years the standard procedure (also mentioned in this thread) is "front wheels kept centered, foot on brake, select Neutral, select Diff/s Unlock, then select opposite drive (Fwd or Rev) & slowly drive max 10M. If "Diff Lock" condition remains, use same procedure, but opposite gear selected for max 10M. (But read specific manual).

Disconnecting the battery ("Cont - Alt - Dete") suggests a computer glitch, rather than classic mechanical "drive line wind-up".