Diff Lock Indicator flashing when truck started and while driving (2 Viewers)

[mark71]

This 'glitch' happens to my truck often, but only bothers me when it won't let me switch into or out of 4LO.

To reset, disconnect your battery for a few minutes. This has worked for me both times I've tried it (not statistically robust, but a place to start).

I suspect it is a software bug and the reason why it throws no codes and reseting fixes it. Never has stranded me, so not too worried.

Keep us all posted.

 

[lmud]

I've had this problem as well. Took it to the dealer and they tried to blame it on my knee hitting the button which I knew wasn't the problem. They checked everything and there were no codes. I just ignore it now when it happens every few months.

 

[JosiasZ]

Hi Mark

Thanks for your comment. I disconnected a couple of times (taking in my batteries and when swapping with friend) - were out for about 40 minutes each time, but still no luck.
I hold my thumbs for tomorrow morning, just to get it to 4H again to be able to move.

 

[Markuson]

I've had this problem as well. Took it to the dealer and they tried to blame it on my knee hitting the button which I knew wasn't the problem. They checked everything and there were no codes. I just ignore it now when it happens every few months.

Same happened a few times on my 08.
One time it stayed stuck in 4LO for numerous attempts to shift back, and I was afraid I'd have to limp home in Lo. Eventually it did shift after several shut-downs and re-starts.

Couple other times it shifted properly but the light stayed on. Shutting down and restarting fixed it.

I wish the 200 had a manual shifter between Hi & Lo like my 100 had. All electrical feels iffy with these occasional glitches.

 

[LCHardriver_02]

Agree with the wish for a manual shift on the transfer case!

 

[JosiasZ]

Great news!! My cruiser is back from the dealers and it works 100%. Not yet tested off-road.
They were the second dealers to confirm it was the actuator on the center diff, which also affects the 4L / H function as well as the cruise control.
Gearbox, Front and Rear diff oil changed to check for iron filings / damage - none found.
Hats off to Toyota South Africa that picked up the bill for the parts and Barloworld Toyota Centurion for the reduced labour charge. As the problem fist appeared at 55 000km, they agreed it should not have happened and backed their product.

 

[Markuson]

Great news!! My cruiser is back from the dealers and it works 100%. Not yet tested off-road.
They were the second dealers to confirm it was the actuator on the center diff, which also affects the 4L / H function as well as the cruise control.
Gearbox, Front and Rear diff oil changed to check for iron filings / damage - none found.
Hats off to Toyota South Africa that picked up the bill for the parts and Barloworld Toyota Centurion for the reduced labour charge. As the problem fist appeared at 55 000km, they agreed it should not have happened and backed their product.

Nice to hear.

 

[LCHardriver_02]

@JosiasZ - Any ideas as to how we can get our local dealers to "see" the same thing? Most of the ones that I have heard about, including mine, have all been intermittent and clear as soon as the dealer shuts the engine off. They then tell me that the techs cannot troubleshoot it.

 

[bamachem]

My 08 does it too. Been doing it since I got it 17 months ago with 120k on it. 161k and counting now and no real side effects. If it bugs you, just let it warm up then restart. I fixed mine for a while by unplugging the transfer case harness and plugging it back in. I think the ECU isn't getting feedback from the center doff and goes into a sensor fault mode. Clean that connection and it may fix your problem. I didn't clean mine, just unplugged and replugged and it came back.

 

[triplenet]

my 2008 does it as well.... Thought it was my knee also - but I knew I wasn't hitting it.... Think I shift into drive,, back to neutral, turn off car,, and it goes back to normal..

My cruise control doesn't work when its flashing - and it always happens right before a long drive ... like it knows and wants to mess with me

 

[BTUMAN]

My 08 does it too. It's a gremlin for sure but seems to have no ill effect. I always clear it before I drive. Have we determined it is early models?

 

[JosiasZ]

@JosiasZ - Any ideas ......

It is always difficult to have the dealers see an intermittent fault.

My opinion is, when something does not work 100% get it fixed as it is a symptom of something that is about to happen, because you never know when will be the last time it works. With any luck it will happen at home or close to a dealer, but we all know that is never the case - it will be somewhere remotely.

My case (I recommend you try this at a "convenient" place - not out on a trip):
It use to sort itself out after the car has warmed up, until one day that it tried the following:
1. I started the car, light blink, drive around 20km, switch off, switch on, light stop blink - thought all is OK.
2. Switch to 4L, move 5m back and forth to ensure 4L engaged, press center diff switch to check, light blink and since then did not stop blink.
3. Car stuck in 4L and center diff light blink.
4. I have tried for a week where i would start the car and let it idle for 20 mins, neutral, roll in straight line back and forth, changed the batteries, unplugged clean and connect the plugs again - all with no luck.
5. I did not want to drive it on tar to warm up as might cause damage to gears in diff whilst in 4L.
6. Dealer came to my house to check and tried their tricks - no luck.
7. I called a low bed to take the car in.
8. Center diff actuator replaced - now working 100%.
9. As precaution / indication of damage, we also replaced all diff oils and gearbox oil to check for steel filings - none was found, thus no sequential damage.

If the above does not "work" to highlight the problem, it might be worthwhile to leave the car at the dealers overnight and let them start it up early morning and hope the problem shows itself. The problem they explained to me is that it is a closed unit and you cannot replace only a component on it. It could either be an electrical or mechanical problem - they replaced the complete unit.

Hope this helps - keep us updated.

 

[JosiasZ]

Here are some pics of the actuator. I see there are some bolts to open, but you cannot buy only the parts - it is sold as a unit.

 

[Willy beamin]

whats the damage $ on that fix?

 

[JosiasZ]

Parts was R14 000 (ZAR) or $1 244 (AUD)
Labour was R4 000 (ZAR) or $355 (AUD)
Total cost R18 000 (ZAR) or $1 600 (AUD)
Sound a lot less expensive in AUD

 

[Beano]

Just found this thread. Something similar is happening to my wife's 2006 LC where the CDL locks randomly. Only right after she turns it on, but the dash lights are solid and not flashing, and it is definitely engaged. It usually takes several attempts to get the CDL to disengage. Happens about once a week. Dealer has no idea why. She's not engaging it in error as it has happened to me as well and the CD was definitely locked when I drove it. It will engage and disengage normally when we initiate it.

Any help would be appreciated.

 

[mark71]

Might want to try posting in the 100 section.

 

[EODTam]

The same thing happens in my 2011 LX. I've noticed it before a year or two ago. I always just shift back into park and then shut the engine off and then back on. When the car is back on the center diff blinking is gone.

 

[LCHardriver_02]

Mine started like yours @EODTam , but has progressively become more complicated. Now, I need to drive for a bit before it will reset. Also, now I'm getting other weird electronic indications:

horn honks when scanning on the radio

radio keeps changing sources - both driving and sitting at a stop light

AC will not turn on when diff lock is flashing

drive train will not shift between 4Lo an 4 Hi when diff lock is flashing

an alarm goes off after locking the doors (while walking away from truck... not sitting in it)

I'm getting annoyed by this truck...

 

[linuxgod]

Mine started like yours @EODTam , but has progressively become more complicated. Now, I need to drive for a bit before it will reset. Also, now I'm getting other weird electronic indications:

horn honks when scanning on the radio

radio keeps changing sources - both driving and sitting at a stop light

AC will not turn on when diff lock is flashing

drive train will not shift between 4Lo an 4 Hi when diff lock is flashing

an alarm goes off after locking the doors (while walking away from truck... not sitting in it)

I'm getting annoyed by this truck...

My first though is that you have a bad ECU. Which one is the question. I looked at the GSIC because you've peaked my curiosity. (It is Land Cruiser focused. not LX, and doesn't have the 3UZ engine but I've found it's normally pretty close). Also because my CDL started flashing about once per week on startup recently, so I'd like to see a resolution here in case my issue gets worse.

FWIW I'm wondering if you actually have two issues here.

Some of the wiring diagrams show connections between tons of different systems (ECUs, sensors, switches, etc). However, the horn honking when you change the radio source is interesting because the wiring diagram for the horn is VERY simple - the horn goes through the steering pad switch (which I beleive controls the radio and cruise control as well) and to a relay without input from dozens of different sensors:

http://moranbahweather.com/toyota/ewd/ewd/contents/system/main/SYS080.html

Does the horn honk when you change sources (press the MODE button) on the steering wheel, or on the dash (or both)? If the switch in the steering wheel is bad that would explain why the horn honks when you change the radio and why the radio randomly changes sources. The theft warning system also links into the security horn relay (which links into the horn through the certification and main body ECUs). If there's a short to ground it could be completing the circuit and triggering the random alarm, though I have less confidence in that.

The CDL, 4Hi/4Lo drivetrain switch, and A/C seem like they would be related. IF your issue was just the first two I would look into a bad transfer position switch or bad transfer actuator. One system all 3 share (and actually so does the alarm) is the skid control ECU.

http://moranbahweather.com/toyota/ewd/ewd/contents/system/main/SYS015.html
http://moranbahweather.com/toyota/ewd/ewd/contents/system/main/SYS042.html
http://moranbahweather.com/toyota/ewd/ewd/contents/system/main/SYS069.html

All that said everything pretty much eventually touches the main body ECU, so if there's a failing component that's causing weird voltage or resistance readings in some input in the ECU it may not show up in the failing system at first and thus it will be very difficult to find.

So in summary I would:

1. Disconnect and/or replace the steering pad switch (which the horn and radio controls both use)
2. See if you can find a test procedure for the skid control ECU and for the transfer position switch and actuator in the GSIC (typically involves disconnecting a relay or switch and shorting two pins with a paper clip), or take it to a reliable Toyota dealer with a good mechanic who knows how to troubleshoot this.
3. Failing #2, just replace the skid control ECU. The part is probably $300-500 new and it's a crapshoot but if you're desperate for an answer this seems like the likeliest place to start