LINY4Runner

Wondering if anyone has experienced this...my 4WD has been working perfectly, been wheeling quite a few times since installing the front diff.
Last week we got a little snow, so I clicked the 4HI (AWD for us MultiMode guys) and it's been blinking ever since.
Now it feels like the transfer case is turning the front driveshaft, because I feel it in the driver's front wheel. The truck will pull passenger when on the gas and pull driver when coasting, leading me to believe the ADD front actuator isn't locking the passenger wheel to the drivers.
I figured I'd try it again when it got [slightly] above freezing- but to no avail.
Has anyone had this problem and what have you done to fix it?

eric-the-red

I had the same problem in my 01 last winter. Turned out to be a loose connection in one of the plugs on the transfer case. I would start by checking all of them including the front diff.

LINY4Runner

that's what I've been thinking...it's too cold to be crawling around underneath her, been hoping it'd fix itself...so far, no dice

LINY4Runner

Okay so an update after running the truck on the lift...here's where I stand

Front Driveshaft is powered, driving the driver's front wheel (LSD). Front ADD actuator is not engaging the passenger wheel. 4LO and Center Diff Lock make no difference. Even if I unclick the 4WD button, the front driveshaft is still powered, and drivers front wheel still spins.

Does anyone actually know how this system operates?

Here's what I think: I feel like the transfer case locked as it was supposed to, and the light continued blinking- pending communication and comfirmation with the front ADD actuator. The front ADD actuator has not engaged, therefore it has not relayed the information to the ECU and set the light solid. I think the ECU will not disengage the transfer case until it has heard word back from the front actuator.
Does anyone know if this is correct? It's like the whole system is waiting to hear back from the front diff, who is not answering his phone at the moment.
If this is the way the system operates, could I power the lead on the front diff that tells the ECU it's locked, then unlocked so that it allows the transfer case to unlock?

My next step would be to remove the front actuator and see if it operates as designed, then if it operates with direct manipulation, correct?

I'm starting to think this may be an ECU issue...that's a $1200 ECU... :sobbing:

csnoke

Did you ever figure this out? Any advice on removing or testing the front ADD actuator? I believe mine is bad on my 02 sport 4runner.

I tested it with 12v (pins 2 & 6) and for continuity, but didn't get anything from either test. I also tested the transfer case actuator and it worked fine. I'm inclined to believe front dif actuator is bad. I'm going to climb under it tonight and try testing it some more.

Btw, here's a link (Step 4) on how I tested the front ADD actuator: Link

kaiowa99

Same exact problem, lights continued to blink after trying to engage it in ice conditions. Mine wound up being the actuator..the front driveshaft was removed until the part came in. It came in (had to get it from Puerto Rico), problem resolved.

brian24

@LYN Runner

Are you running all stock? You mentioned that you just installed the front diff.