*Resolved* First AHC Fluid Flush DIY - Stuck in LO with Check AHC Error

[ExpeditionMan]

Alright folks... did an AHC flush on my 2013 LX570 following a process on ih8mud. First start up after bleeding at all four corners I received the check 4-wheel AHC system warning and the truck stays in low. I hear the pump click on for a second at start up then the check AHC warning displays and the pump stops. The expansion tank level is still well above maximum (in anticipation of the draw down as the pump replaces the fluid removed during bleeding). Note I did bleed all four corners before starting the engine, rather than starting and idling after each corner. Reading the tips at the end of DIY I used shows a code can occur in this situation...

I assume my only option is the find an indy with a tech stream to clear the code and activate the pump. Other thoughts or options that I can DIY? Is there an at home method of accessing the tech stream? Not against purchasing the necessary cables or software. Located in DFW if anyone is local and wants to help a fellow enthusiast out.

 

[eatSleepWoof]

Check my build thread for dealings with the same issue some years back.

Was the reservoir ever empty, or did you keep it full of fuel at all times? If it was ever empty you may have an empty AHC pump, and it's NOT self priming. If you don't prime it manually it WILL burn out and will cost big $$. (That shouldn't be necessary if you did not have an empty reservoir.)

VXDiag is the cable you want to buy, it'll come with a CD that has Techstream on it.

 

[ExpeditionMan]

Check my build thread for dealings with the same issue some years back.

Was the reservoir ever empty, or did you keep it full of fuel at all times? If it was ever empty you may have an empty AHC pump, and it's NOT self priming. If you don't prime it manually it WILL burn out and will cost big $$. (That shouldn't be necessary if you did not have an empty reservoir.)

VXDiag is the cable you want to buy, it'll come with a CD that has Techstream on it.

Fluid level was never below mid-point of max and min (start of process). I then added extra fluid until expansion tank was nearly full per the DIY instructions (added 1.5 quarts).

I will review your build thread shortly.

Is this the VXDiag I want? Based on the reviews it seems incredibly sketchy.

 

[radman]

As you already pointed out, your issue is that you didnt start up after each corner and let the pump do it's thing.

All you need to do is get techstream and clear the pump code so it will refill the system. how tech savvy are you 1-10?

FAQ - How-To: TechStream In 5 Minutes

forum.ih8mud.com

 

[eatSleepWoof]

Fluid level was never below mid-point of max and min (start of process). I then added extra fluid until expansion tank was nearly full per the DIY instructions (added 1.5 quarts).

I will review your build thread shortly.

Is this the VXDiag I want? Based on the reviews it seems incredibly sketchy.

That's the one. You can get it a bit cheaper from their own site, but it'll be slower to ship.

The reviews all mention malware being present on the supplied CDs - entirely possible. I didn't have such issues when I used it, but I also installed it on a copy of Windows that I used for nothing else. Given the numerous reports you'd be wise to do the same, or install it within a virtual machine running Windows. The software itself works great.

 

[ExpeditionMan]

Check my build thread for dealings with the same issue some years back.

Was the reservoir ever empty, or did you keep it full of fuel at all times? If it was ever empty you may have an empty AHC pump, and it's NOT self priming. If you don't prime it manually it WILL burn out and will cost big $$. (That shouldn't be necessary if you did not have an empty reservoir.)

VXDiag is the cable you want to buy, it'll come with a CD that has Techstream on it.

Also I'm 99% sure description 1 from this post in your thread is my issue. I should have allowed the pump to refill the accumulators between bleeds.

 

[ExpeditionMan]

As you already pointed out, your issue is that you didnt start up after each corner and let the pump do it's thing.

All you need to do is get techstream and clear the pump code so it will refill the system. how tech savvy are you 1-10?

FAQ - How-To: TechStream In 5 Minutes

forum.ih8mud.com

Tech savvy enough to do this, but starting to think the indy down the street could just plug in the tech stream and have me fixed up in 15 minutes.

 

[chriscosta416]

I commented on your FB thread, let us know how it goes.
You probably have a clogged actuator valve probably from old dirty fluid.
Once a code is thrown the error appears and AHC stops working.
If you drain too much at each corner usually this happens
Immediately start the truck and turn the height switch to H multiple times. It might take a few starts but that’ll usually clear the valve. Or if you have Techstream you can manually actuate it and clear codes

 

[paulunm]

I commented on your FB thread, let us know how it goes.
You probably have a clogged actuator valve probably from old dirty fluid.
Once a code is thrown the error appears and AHC stops working.
If you drain too much at each corner usually this happens
Immediately start the truck and turn the height switch to H multiple times. It might take a few starts but that’ll usually clear the valve. Or if you have Techstream you can manually actuate it and clear codes

I came here to say this, flicking to H several times on startup worked for us.

 

[ExpeditionMan]

I commented on your FB thread, let us know how it goes.
You probably have a clogged actuator valve probably from old dirty fluid.
Once a code is thrown the error appears and AHC stops working.
If you drain too much at each corner usually this happens
Immediately start the truck and turn the height switch to H multiple times. It might take a few starts but that’ll usually clear the valve. Or if you have Techstream you can manually actuate it and clear codes

I came here to say this, flicking to H several times on startup worked for us.

Confirmed issue resolution with this strategy. Only took one cycle this morning and no more warning. Raises and lowers without issue. I'm going to do a small bleed tonight just to verify clean fluid at all four bleeders, but otherwise mission complete.