Flashing Front Wheels on 4WD Indicator

A

AJF

New Member
Hi all,

I just picked up my 2001 Space Gear on Monday and during my drive home I noticed that the 4WD indicator on the dashboard was displaying 2 flashing green lights for the two front wheels. I verified that I was not in 4WD, and drove the rest of the way home. Since then I have been researching the issue and I keep reading about the A & B solenoid valves as the possible culprit. I looked at the valves today and verified the hoses were well connected, and also climbed under the car to verify that were seating correctly on the little vacuum canister (not sure what this is called, still learning). Anyway, all of that looked good. Does anyone have any trouble shooting tips or suggestions? I am thinking about ordering the solenoids and replacing them to see if that clears it.

Any help would be greatly appreciated!

Here are the replacement valves I was looking to order, https://www.aliexpress.com/item/32867964993.html probably not a good idea to go with ones so cheap but they looked really similar to what is currently installed.

Thanks all!
 
@AJF most likely you are in 4wd and the lights there are blinking because when it was shifted back into 2wd there was no enough air pressure to cause the switch to move and disengage the front axle. So the lights blinking mean that its in 4wd and is trying to switch out of it.

Best way to make sure is to shift it into 4wd and see if the lights turn solid. If so then most likely its the solenoid. If you shift into 4wd and they keep blinking you have other issues.

1st place to start is to find a solenoid replacement. I ordered this from Amazon had it in 2 days and switched it out in under an hour and it fixed my problem. https://www.amazon.com/gp/product/B07JYYNQQZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

If that doesn't fix it then you need to check your lines and make sure they are not leaking and make sure that the switch up under your transfer case is in good working order.

-Sean
 
Thank you for the feedback Sean. I did the first part you mentioned the night the error popped up and confirmed that the vehicle goes into 4WD (got the solid green lights) and back into 2WD when I shift back (this is when they start flashing). I have been driving it around town for the last few days and it doesn't feel like I am in 4WD but the flashing lights have not gone away. I am going to look at the link you sent me and get back under there to check the lines and switch under my transfer case. If nothing appears to be obviously wrong under there, I will send off for the new solenoids.

Thanks again!
 
Did you drive in reverse after shifting back to two wheel drive? Sometimes I need to do this. Otherwise it potentially is one of the many switches on drivetrain
 
  • Like
Reactions: AJF
I did not try reversing after shifting back into 2WD, I am going to try this out today. I will follow up and let you know if it clears.

Thanks!
 
My L400 has the same issue, I've tested it out and confirmed that the 4WD is engaging and disengaging correctly so I've just been driving with the flashing lights for the last year. I did find this a troubleshooting guide for similar Mitsu models, and the steps should be roughly the same, just haven't gotten around to doing it yet. Hopefully it helps! http://4wd.blogeasy.com/article.view.run?articleID=318776
 
I had the same issue with my "new" 99. The reverse trick worked to get the hubs to unlock and flashing to clear. I had to drive in reverse significantly farther than I thought would be necessary FYI.
 
  • Like
Reactions: AJF
I went out and bought a new solenoid valve and was going to install it this past weekend and wouldn’t you know it, the error cleared! I am not sure what happened but I now have two solid green lights! I guess the true test to see if it’s resolved now is to cycle through all my 4WD settings and see if it remains cleared when I shift back into 2WD.

Appreciate the feedback :)

Have a good one
 
Just curious, I have a 1996 and when engaged in 4 wheel drive only the two front wheel light indicators is on. Is that correct? Do the rear wheels on the dash indicator not light up?
 
ronsjc said:
Just curious, I have a 1996 and when engaged in 4 wheel drive only the two front wheel light indicators is on. Is that correct? Do the rear wheels on the dash indicator not light up?
Click to expand...
Since the rear wheel lights are on 24/7 as its always in rear wheel drive, they burn out pretty quick. Maybe 40-50k miles and they go out.

If you take the dash apart to replace them you might as well replace both the bulbs for the rear and front lights at the same time.
 
Backdoor said:
@AJF most likely you are in 4wd and the lights there are blinking because when it was shifted back into 2wd there was no enough air pressure to cause the switch to move and disengage the front axle. So the lights blinking mean that its in 4wd and is trying to switch out of it.

Best way to make sure is to shift it into 4wd and see if the lights turn solid. If so then most likely its the solenoid. If you shift into 4wd and they keep blinking you have other issues.

1st place to start is to find a solenoid replacement. I ordered this from Amazon had it in 2 days and switched it out in under an hour and it fixed my problem. https://www.amazon.com/gp/product/B07JYYNQQZ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

If that doesn't fix it then you need to check your lines and make sure they are not leaking and make sure that the switch up under your transfer case is in good working order.

-Sean
Click to expand...
Read the comments in the Amazon listing for more info on this issue.
 
Not saying it's the exact same thing but we just diagnosed an identical issue and it was the solenoids. The easiest way to confirm that is with a vacuum gauge directly to the 4wd vacuum line (the outlet side of the solenoids) and see if the front wheel lights stop flashing in 2wd with the KOEO and vacuum applied. If the light goes out with a manual vacuum applied and comes back on when you release the vacuum you've got your problem! The solenoids can click and still not do their job correctly, so don't rely on that.

Even if it fixed itself temporarily I'd get this replaced, you wouldn't want the solenoid to fail while driving and drop you into 4wd at highway speeds as these do default to engaged if the vacuum or solenoid fails. These are common failure components so even if you don't have the testing equipment it's a pretty safe bet the solenoids are your issue. If it comes back with new solenoids you've got something else going on and I'd be looking at your vacuum lines or power to the solenoids next.
 
B.Delica said:
Even if it fixed itself temporarily I'd get this replaced, you wouldn't want the solenoid to fail while driving and drop you into 4wd at highway speeds as these do default to engaged if the vacuum or solenoid fails.
Click to expand...
I was under the assumption that the 4wd select was physical engagement and the solenoids controlled the indicator lights. Is this untrue? Doesn't the 4wd lever physically select Hi/Lo and engage the center diff lock?
 
The solenoids control the vacuum to the front diff actuator which engages the front diff to the front CV axles. So the front axles are always turning no matter what you're in, then the actuators lock the axles into the front diff when you select 4wd. The shifter mechanically engages the T case and causes the front driveshaft to start spinning, in turn moving the internal gears on the front diff, and spinning the now engaged CV axles.
 
Don’t the hubs disengage when rolling backwards? I believe those with auto hubs this would allow the cv axles to not engage at the wheel hub along with the facts you stated above
 
That's only on the L300s, the actuation on the 4wd system is solenoid and vacuum operated on L400s instead of mechanically operated like the L300's so it doesn't have that dead zone. The 300 hubs have a "ramp" in the auto hub lockers that spline in and out and when you switch directions and the CV's are turning (the vehicle is in 4wd). If you reverse, it essentially screws out, then screws back in resulting in a point in the middle that it's not engaged at all. All of this is happening at the hub/cv connection.

L400's have a solenoid-operated system that engages directly at the front diff instead of out at the hubs which solves this dead zone problem, but the solenoids can fail so it's an improvement in some ways and creates new failure points in other ways. So your CV axles on L400 auto hubs are turning with the wheels, but only getting gear power when you shift to 4wd and everything engages and starts turning.

Now if there's another issue with the drivetrain being bound up when you shift out of 4 into 2, that would make sense. For example, being in 4wd on a dirt road, getting onto asphalt, shifting to 2wd with the drivetrain bound up, then having to go in reverse or drive it for a bit to unbind the drivetrain which would then allow it to drop the rest of the way into 2WD. My 97 GMC truck has the same issue if I try to shift out of 4 on asphalt and this is typical on 4wd systems.

Edit* the vacuum solenoid power that engages and disengages the front diff doesn't really have any real power, so it absolutely won't be able to overcome the bound drivetrain. This would line up well with what some people said above about having to reverse it to disengage. You'd either need to back up for a while to unload it or drive in a straight line for a while. Also having really dirty gear oil could cause a lack of lubrication which would put more stress on the sleeve that engages the front diff causing a "sticking" in 4
 
B.Delica said:
The solenoids control the vacuum to the front diff actuator which engages the front diff to the front CV axles. So the front axles are always turning no matter what you're in, then the actuators lock the axles into the front diff when you select 4wd. The shifter mechanically engages the T case and causes the front driveshaft to start spinning, in turn moving the internal gears on the front diff, and spinning the now engaged CV axles.
Click to expand...

I understand better but not fully. I need to search out an exploded view of the front diff. I have been considering doing a manual hub swap on my L400 after seeing Doc Wong's upgrade/build thread. Is it worth it or does it add unnecessary complexity to the automatic system?
 
You must log in or register to reply here.
Top