New AHC question, maybe… (1 Viewer)

[Zakowsky]

So I have read the epic amount of info on the AHC and its problems, but this is a fairly rare one, I think. 2003 LX470. I have the flashing OFF light, but the AHC, and the on/off button still work fine. It’s strange, I start the engine, the OFF light starts flashing, but if you hit H or L from N the AHC goes there and the flashing green light goes solid and all is fine. Press the OFF button for a second, and the H/L controls don’t work anymore – but the OFF light keeps flashing. Press the button for a second again, and the controls start working again, just like they should. But the OFF light won’t stop flashing.

I vaguely remember reading a post somewhere about a problem with the circuit board on the console having a flaw that can cause this but I just can’t find it anymore. Since the AHC system itself seems to be working fine, I figure it is either the switch in the cab, the AHC control unit, or something in the ECU. All fuses are fine. Any ideas would be appreciated.

Btw no codes on standard OBD2 - my 50$ miniVCI Techstream clone cable died and I can't pick a winner from the several hundred versions for sale online - any suggestions for ones that actually work would also be appreciated.

Thanks,

Mike

 

[suprarx7nut]

Without AHC data, this is a dead end.

Pick a cable with decent ratings. Or two. Or three.

Gotta get plugged in or check codes the old fashioned way.

 

[Zakowsky]

Yeah, just so sick of online OBD2 crap these days – I contacted OBDII365 about my dead cable and they wanted video proof that it was dead, photos weren’t enough. For $40 I just threw it in the garbage…but yes, I really need to replace it now.

New development is I found the article about the circuit board, but that wasn’t my problem. And now it won’t go up and down any more, even with my button trick. Great. And I still have 2 new CV joints sitting in boxes waiting to install…oh well, will update when I get some codes.

 

[suprarx7nut]

Get yourself a connection to Techstream. IMO, connecting to techstream is worth upwards of ~$500-1000. This varies with the value of your personal time, but the difference between having Techstream and not is *immense*. It's not just a slightly better way to work with the system, it's a complete game-changer.

You probably have a simple problem that will quickly be identified with techstream.

For any of the cables, do not use the software that comes with the cable. Only use the software posted on mud in the "5 minutes" thread.

 

[Zakowsky]

Thanks, I hadn’t seen the 5 minute thread. It’s frustrating, Techstream used to work fine, and now I’ve tried 4 different versions of Techstream, X-Horse Firmware Update Tool reports it is fine (MVCI006000001, Firmware 1.4.1), the green light is on on the cable, but it just won’t connect to the control units. My Bluetooth OBD2 connects fine with Torque so it’s not the port.

I think I just need to re-flash the firmware on the cable, but I can’t find MVCI006000001.hex anywhere on the net. MHH auto has it but forget getting a membership there it seems. Does anyone have a copy of this firmware? Thanks.

Update - found the firmware! Going to give it a try. If anyone needs a copy pm me.

 

[smoltz]

https://www.amazon.com/dp/B097YC5LSR?psc=1&ref=ppx_yo2ov_dt_b_product_details

That's the one I have, works fine.

 

[Zakowsky]

Thanks smoltz; I re-flashed mine, the green light flashes and it seems to be ok but it still doesn't work with Techstream. I give up and will get a new one.

 

[suprarx7nut]

Thanks smoltz; I re-flashed mine, the green light flashes and it seems to be ok but it still doesn't work with Techstream. I give up and will get a new one.

On both of my cables, I commonly have to plug and unplug a few times to get the xp operating system to detect the USB input. Have you tried unplugging and replugging slowly like.... literally 20 times?

That appears to be a quirk of the virtual machine setup from that thread. It's behaved the same way for me across multiple laptops and multiple cables on many different 100 series vehicles I've connected to.

 

[Wilsil]

How-To: TechStream In 5 Minutes

Getting Techstream up and running can be a bit of a pain. Hopefully this helps someone get started quickly. Step 1: Purchase an OBD-II / Mini-VCI interface. - I have sold out of my cables and supply chains are back in order, so no reason to purchase more. Anything like this will work: Mini-VCI...

forum.ih8mud.com

Here is the link

 

[Zakowsky]

It seems to recognize it fine; I try 3 different VM’s, running 17.10.012 (which came with it) and on another running 13.00.022, both under Win 7 32 bit. I also try 12.20.024 from here on XP. The only thing I am not too sure of is under Device Manager the com port is listed as having the FTDI driver, but it also sometimes shows up under Vehicle Interface Module, as a WinDriver from someone named Jungo…

I re-flashed the cable with Flash Magic, verified it and read the ROM back no problem. One weird thing that has always happened is Techstream has always failed to recognize the vehicle as an LX470, and I have to enter it by hand. But the cable flashes between red and green when it is trying to figure out what the car is. But it definitely fails the Cable Test on the K line.

I have even tried changing the latency on the serial port and all that, nothing makes it work in Techstream. If my Bluetooth OBD2 didn’t work I would really think it something wrong with the car’s port. But first I will try another cable.

 

[Zakowsky]

So an update; first thanks for the recommend smoltz, I got that exact cable and it works perfectly, it seems better then the OBDII365 ever did in fact.

The codes were C1736 and C1764, and there are lots of threads on this. Hopefully a broken wire, as some were lucky enough to have. Will investigate.

I also had a C1234 Yaw Rate Sensor code; I hope this was generated as a result of the AHC problems, and a Zero calibration fixes it. The price of that sensor in Canada is over $1,110…ridiculous.

Also wanted to add, on the off chance people with AHC problems haven’t seen this, I have a lot of LX repair manuals but this is amazing; over 1200 pages just on the LX AHC, and easy to follow.

http://myfirewood.com/LEXUS/LX/rm08g5e/PDFs/RepairManual-Suspension.pdf

Will update when I look closer at things.

 

[IndroCruise]

So an update; first thanks for the recommend smoltz, I got that exact cable and it works perfectly, it seems better then the OBDII365 ever did in fact.

The codes were C1736 and C1764, and there are lots of threads on this. Hopefully a broken wire, as some were lucky enough to have. Will investigate.

I also had a C1234 Yaw Rate Sensor code; I hope this was generated as a result of the AHC problems, and a Zero calibration fixes it. The price of that sensor in Canada is over $1,110…ridiculous.

Also wanted to add, on the off chance people with AHC problems haven’t seen this, I have a lot of LX repair manuals but this is amazing; over 1200 pages just on the LX AHC, and easy to follow.

http://myfirewood.com/LEXUS/LX/rm08g5e/PDFs/RepairManual-Suspension.pdf

Will update when I look closer at things.

Very good information -- it is for LX570 AHC -- which is quite a bit different to LX470 AHC -- meaning 200 series, not 100 series ....

 

[Zakowsky]

I was just reading through the diagnostics and didn't realize that right away. Didn't know they were so different - was just impressed with the level of detail. Now to dig the ice away from the accumulator and look at the wiring.

Update: just looked at the accumulator - on one end there is a wire that is broken off; not the big well protected one that goes into the solenoid at the front, but some flimsy connector with one or two wires. Can't see it being this important (or it would be better protected) but who knows. Can't fix this in the slush so going to get it cleaned off and into the garage.

 

[IndroCruise]

I was just reading through the diagnostics and didn't realize that right away. Didn't know they were so different - was just impressed with the level of detail. Now to dig the ice away from the accumulator and look at the wiring.

Update: just looked at the accumulator - on one end there is a wire that is broken off; not the big well protected one that goes into the solenoid at the front, but some flimsy connector with one or two wires. Can't see it being this important (or it would be better protected) but who knows. Can't fix this in the slush so going to get it cleaned off and into the garage.

Suggest take a photo and upload it for comment ....

 

[Zakowsky]

Got it into a garage and dried off a bit. On closer inspection it looks like this has been repaired in the past. There is not very much wire coming out of the body, and this doesn't look so easy to fix. Guess I will cut the one good wire, extend it getting a soldering iron up there and try and get two leads back on the plug. Seems busted off inside. Does the other side of the connection lead inside the accumulator? So this is part of the AHC wiring?

 

[Jeremy9A]

That is likely the wiring for the accumulator pressure sensor on the end opposite side of the accumulator. The system would definitely not operate without that sensor information.

 

[Zakowsky]

Thanks Jeremy. Just got the truck up on ramps, will help with access. Time for surgery.

 

[Zakowsky]

Huzzah! That was it – soldered new wire extensions onto the stumps coming out of the frame, rebuilt and rewired the decayed connector, some heat shrinkable tubing and AHC is fully functional again, cleared the codes and they didn’t come back so all good. Though as all can see from the rust we face up here I am sure something else will go soon but for now we are back on the road. Still have to do the Zero point calibration but will leave that for tomorrow. Thanks to all for the input. Time for a beer!