AHC Removal - Fuses vs ECU

[Fancy Pants]

Looking over this thread I just have a couple questions. I have a 2003 LX so wondering if anyone knows of any differences from what is described here?

Looks like the consensus was remove the 50 amp fuse under the hood and the two lower plugs from the ahc box. Does that still hold true for my 03?

Do I need to disconnect the battery before doing that?

Also related to this - Before I removed the AHC, the previous owner had put the manual override on the system to lock it in high. Ever since I've had it the telescoping steering wheel didn't work. I can adjust up and down but not in and out. Since it seems there are some correlations does anyone have a theory?

 

[customcruiser]

I still have my fuses removed and no problems.

He probably turned off the telescoping option with TechStream - many do this to save the motor.

 

[jLB]

Looks like the consensus was remove the 50 amp fuse under the hood and the two lower plugs from the ahc box. Does that still hold true for my 03?

Do I need to disconnect the battery before doing that?

Since it held true for both my 99 and 06, I would expect an 03 to be the same.

You might get away without disconnecting the battery, but out of caution/habit, I did disconnect the negative terminal of the battery before pulling the plugs.

Also related to this - Before I removed the AHC, the previous owner had put the manual override on the system to lock it in high. Ever since I've had it the telescoping steering wheel didn't work. I can adjust up and down but not in and out. Since it seems there are some correlations does anyone have a theory?

I suspect that your "telescope" issue is unrelated. It's not uncommon to have either the "tilt" or "telescope" motors go bad over time, here's a thread that might be of interest:

DIY: Telescoping Column Motor Removal/Repair

The telescoping feature of my tilt column starting slowing down and making lots of noise soon after I purchased a 2004 Land Cruiser. I initially thought it was the tilt but soon after investigation I pinpointed it to the telescoping part. It has super low miles and was well cared for but I was...

forum.ih8mud.com

 

[ghong14]

Only thing you need to do is unplug one plug from ahc computer. Nothing else needed

Can you tell me which plug needs to be pulled?

 

[jLB]

Can you tell me which plug needs to be pulled?

I believe @birch hill is referring to the bottom plug on the AHC ECU.

A thread that points out the location of the AHC ECU:

My 2006 Land Cruiser AHC to OME experience

Just wanted to share my experience of converting AHC to OME. Parts OME2860 OME Coil Spring - Rear N60000-S OME Nitrocharger Sport Shock - Front N60002-S OME Nitrocharger Sport Shock - Rear OME303001 OME Torsion Bar Set SPC-25455 SPC Adjustable Upper Control Arms SOK006 SLEE - Differential Drop...

forum.ih8mud.com

Based on what I saw in tech stream, and wanting to kill power to the underhood pump connector, I ended up pulling the bottom two connectors on the AHC ECU, and pulled the 50a underhood AHC fuse.

 

[ghong14]

Has anyone tried just pulling the 3 plugs on the driver side for the AHC system? Check out the following video

 

[jLB]

Has anyone tried just pulling the 3 plugs on the driver side for the AHC system? Check out the following video

That should work too, (you’re just pulling one more plug to the AHC ECU, that for all intents and purposes is “dead” from pulling the first two plugs) although I’d still “kill” the power to the pump connector by pulling the 50a fuse.

 

[ghong14]

That should work too, (you’re just pulling one more plug to the AHC ECU, that for all intents and purposes is “dead” from pulling the first two plugs) although I’d still “kill” the power to the pump connector by pulling the 50a fuse.

What is the difference between the first 2 vs the last one? When you are referring to the first 2 are you counting from the bottom up or top down?

 

[jLB]

What is the difference between the first 2 vs the last one? When you are referring to the first 2 are you counting from the bottom up or top down?

The difference? The wires that are connected to them, what they do, and where they go?

After pulling the "bottom two" connectors, the AHC ECU quits communicating with the rest of the system. If it makes you feel better to remove the third (top) connector, and/or completely remove the AHC ECU, I don't believe it makes any difference, but it's not going to hurt anything either.

 

[ghong14]

The difference? The wires that are connected to them, what they do, and where they go?

After pulling the "bottom two" connectors, the AHC ECU quits communicating with the rest of the system. If it makes you feel better to remove the third (top) connector, and/or completely remove the AHC ECU, I don't believe it makes any difference, but it's not going to hurt anything either.

Thanks this is super helpful. Just don’t understand why it is suggested to also pull the fuses if the system no longer communicates. Is it because the power to the AHC is still on?

 

[jLB]

Thanks this is super helpful. Just don’t understand why it is suggested to also pull the fuses if the system no longer communicates. Is it because the power to the AHC is still on?

The only fuse that I pulled, is the underhood one, that provides power to the AHC pump. It might not be absolutely necessary, but having a potentially "hot" wire bouncing around underhood, that wasn't needed, made pulling the fuse seem like the "right" thing to do.

The driver's side kick panel AHC fuses were left in place.

 

[Fancy Pants]

Following up after doing mine.... I removed the large fuse under the hood. Then unplugged the two bottom wires on the ACH unit under the steering wheel. All the lights went out, basically making it invisible on the dash. No error lights or anything wonky, just gone.

As has been mentioned it is a very tight fit to reach the ACH box, I couldn't have done it with my hands. I just used a screwdriver to push the release and then twisted the screwdriver and slowly worked the two plugs out. Took a couple minutes max.

 

[bushwack]

I just deleted my AHC sadly and put in an Ironman FCP setup. To turn the blinking light off I disconnected the bottom two plugs as described above. To make it easier to get my hands in I removed the nut holding the metal unit to the bracket which allowed more flex to wiggle my hand up there. I didn't remove any fuses. So far so good.

 

[blackthecrowes]

I just deleted my AHC sadly and put in an Ironman FCP setup. To turn the blinking light off I disconnected the bottom two plugs as described above. To make it easier to get my hands in I removed the nut holding the metal unit to the bracket which allowed more flex to wiggle my hand up there. I didn't remove any fuses. So far so good.

using an old thread

Is the AHC control unit always under the steering wheel - even on right hand drive cars?

 

[blackthecrowes]

using an old thread

Is the AHC control unit always under the steering wheel - even on right hand drive cars?

apparently yes
did it today - a bit different on RHD cars but straightforward