AHC Adventures "Schock" replacement (1 Viewer)

[IceStorm]

Hi everyone.
Wonder if anyone out there has had these issues.
Just removed the front shocks from my LC 100 (AHC). replaced the bushings in the shocks they where totally gone. While I was there I notice that one of my height sensors had literally broken off, Probably when jacking the car up. The arm on the sensor had all but sized up so it simply broke the sensor off it´s base. So I sourced a second hand one that seemed fine and a quick check on it´s resistance seem to confirm that. Anyway I removed the shock, replaced the bushings replaced the front height sensors with ones from a younger LC 100 that had it´s AHC scrapped when it was converted to a Super Jeep on 47" tires. Put everything back in place, opened the bleed valves for each front globe and lowered the car. I added AHC fluid well above the high mark since a lot of oil was lost during the wok, closed the bleed valves and started the car. And noting.... The green light says it´s height is normal and pressing up or down button does noting, the up/down light just blinks. There are no error codes and no sound from the pump.

Has anyone here done this kind of work and perhaps have any ideas on what is bugging the system?
Any ideas appreciated

 

[ihadmail]

When you ha e techstream running, press up or down and look for a change in the "front wheel up" "front wheel down" "rear wheel up" "rear wheel down" boxes. If your actuators are getting an open signal those will change from off to on.

 

[ihadmail]

Also, verify that "height control sw(down)" and "height control sw(up)" turn to on when pressing the switch.

 

[IceStorm]

Also, verify that "height control sw(down)" and "height control sw(up)" turn to on when pressing the switch.

Thanks Will have to check, this is an older LC100 1999 probably OBD I so I may have to visit a dealer to get this info.

 

[ihadmail]

You can buy a cable with a bootleg of techstream for $30. Search the website aliexpress.com for "mini vci 2.0.4" there is only one result, that's the one you want.

 

[ihadmail]

Or, you can take it to a dealer.

 

[PADDO]

Hi everyone.
Wonder if anyone out there has had these issues.
Just removed the front shocks from my LC 100 (AHC). replaced the bushings in the shocks they where totally gone. While I was there I notice that one of my height sensors had literally broken off, Probably when jacking the car up. The arm on the sensor had all but sized up so it simply broke the sensor off it´s base. So I sourced a second hand one that seemed fine and a quick check on it´s resistance seem to confirm that. Anyway I removed the shock, replaced the bushings replaced the front height sensors with ones from a younger LC 100 that had it´s AHC scrapped when it was converted to a Super Jeep on 47" tires. Put everything back in place, opened the bleed valves for each front globe and lowered the car. I added AHC fluid well above the high mark since a lot of oil was lost during the wok, closed the bleed valves and started the car. And noting.... The green light says it´s height is normal and pressing up or down button does noting, the up/down light just blinks. There are no error codes and no sound from the pump.

Has anyone here done this kind of work and perhaps have any ideas on what is bugging the system?
Any ideas appreciated

All three AHC fuses checked ok, system not in the OFF mode or an inhibited state - door or rear hatch open, foot not on brake >5 seconds etc?
What's the actual height status now? In L, on the bump stops or N? And how did you determine there isn't any AHC DTCs noting you can't see them with a standard OBD reader, you have to either read the flashing OFF light codes, use Techstream or something like an icarsoft 905. If the OFF lamp is flashing at a constant .25 Hz then there are no codes stored. If it's flashing in bursts then it's telling you a DTC or two. Did the pump run at all? It's possible you've got a low pressure/air lock fault or potentially one of the replacement height sensors is faulty. Need to work out if the fault is a consequence of the hydraulic work or a control system/height feedback fault.
Anyway I'd start with manually clearing AHC codes (if any) via shorting TC and E1 in DLC1 and checking again. If that doesn't clear the hang up you'd then try the manual pump run procedure to force its operation.

 

[IceStorm]

You can buy a cable with a bootleg of techstream for $30. Search the website aliexpress.com for "mini vci 2.0.4" there is only one result, that's the one you want.

Thanks ihadmail. I will check that out

 

[IceStorm]

All three AHC fuses checked ok, system not in the OFF mode or an inhibited state - door or rear hatch open, foot not on brake >5 seconds etc?
What's the actual height status now? In L, on the bump stops or N? And how did you determine there isn't any AHC DTCs noting you can't see them with a standard OBD reader, you have to either read the flashing OFF light codes, use Techstream or something like an icarsoft 905. If the OFF lamp is flashing at a constant .25 Hz then there are no codes stored. If it's flashing in bursts then it's telling you a DTC or two. Did the pump run at all? It's possible you've got a low pressure/air lock fault or potentially one of the replacement height sensors is faulty. Need to work out if the fault is a consequence of the hydraulic work or a control system/height feedback fault.
Anyway I'd start with manually clearing AHC codes (if any) via shorting TC and E1 in DLC1 and checking again. If that doesn't clear the hang up you'd then try the manual pump run procedure to force its operation.

No warning lights in the dash. system says height is normal. It sits on the stops in the front but is normal in the back. I suspect one of the sensor is faulty. I will try and fix the broken seat on my old one and loosen it a bit up and re-fit it. After reading your reply and a few others I am starting to suspect that the system may not give errors (in the dash) when the hight sensor is faulty.

Thakns PADO I will go over this tonight. and reply if I get this working. Also checking out the techstream ihadmail suggested, if it does not help now it looks like a must for LC owners.

 

[ihadmail]

The system does not give any standard errors in the dash.

With the techstream software you will be able to see all of the relevant parameters to determine what portion of the system isn't working properly. In America, 1/3 hour labor at a dealership will pay for that cable and software.

Feel free to PM me if you have any specific questions about the software, cable or how to use them. @PADDO is THE man for answering AHC questions. Sometimes I wonder if he was an engineer on the development team due to his level of knowledge of the system.

 

[IceStorm]

The system does not give any standard errors in the dash.

With the techstream software you will be able to see all of the relevant parameters to determine what portion of the system isn't working properly. In America, 1/3 hour labor at a dealership will pay for that cable and software.

Feel free to PM me if you have any specific questions about the software, cable or how to use them. @PADDO is THE man for answering AHC questions. Sometimes I wonder if he was an engineer on the development team due to his level of knowledge of the system.

Will do. Thank you ihadmail

 

[PADDO]

With the combination of front on bumps and rear normal, system hung up after swapping in used height sensors I think you'll find a defective front potentiometer. You can swap the good pots onto your better brackets if you can undo the 3 retainer screws and the 10mm lever lock nut. And front and rear potentiometers are the same* (interchangeable is more accurate than same* just different brackets) so if you have access to more spares you can swap then around. To clarify my previous post you need to put it in diagnostic mode (ignition off, Tc and E1 short in DLC1 under the hood, ignition to on - to clear AHC codes bush brake pedal 9 times in less than 3 seconds, ignition off and remove shorting wire) to get the OFF lamp to flash DTC sequences - these can be hard to interpret even when you know what sequence to look for. Height sensor codes notoriously don't reveal themselves - apart from weird height behavior like sitting on bumps or bum up high. Techstream will let you see the feedback to the system as @ihadmail points out.

 

[IceStorm]

Update.
Thanks to @PADDO and @ihadmail

Lifted the car back up. Did not have anything to analyse with "yet" so I decided to take the right hand unit out of the car, I knew my old sensor was working despite it being stiff and broken back plate, so I removed the sensor from the broken place and swapped it with the one I had sourced used. And low and behold, the AHC kicked into life and the front lifted. Added more AHC fluid and lifted to high and then to low and then once more. Everything works great. Now my old right hand unit was still a bit stiff, but I had my old unit from the left side, I cheeked it and it was loose and nice. So I removed the right hand unit once more, took the loose unit out of my old right hand unit and swapped it to the left hand bracket. I then refitted the right hand unit and all again was well. Just to be on the safe side I checked the rear height sensor and it was in excellent working condition. So I now have all new bushings in the front shocks, (I naturally painted them as well) and a working car once more. Thanks to a good friend I had a good shop and a lift to do my work on (and help), or this would have been a lot harder to accomplish.

Image: On the top is the sandblasted bracked that failed, below is the unit I scavenged a good sensor from.

Thanks again

 

[PADDO]

Thanks for the update...you nailed it! Probably $600 repair in the US, assuming you could find someone capable of repairing it without telling you that you needed a new pump, shocks, ECU, accumulators....

When you get your Techstream up and running we will sort your neutral pressures out too. For info, Dorman make an aftermarket OE equivalent height sensor potentiometer (not the complete unit with bracket and short cable, just the actual potentiometer) it's the Dorman 924-755 Headlight Leveling Sensor that bolts straight in - $US 55 off Amazon.

 

[IceStorm]

Thanks for the update...you nailed it! Probably $600 repair in the US, assuming you could find someone capable of repairing it without telling you that you needed a new pump, shocks, ECU, accumulators....

When you get your Techstream up and running we will sort your neutral pressures out too. For info, Dorman make an aftermarket OE equivalent height sensor potentiometer (not the complete unit with bracket and short cable, just the actual potentiometer) it's the Dorman 924-755 Headlight Leveling Sensor that bolts straight in - $US 55 off Amazon.

Thank you @PADDO

 

[ihadmail]

Glad you were able to get it sorted out for no additional $$$$$

 

[IceStorm]

When you ha e techstream running, press up or down and look for a change in the "front wheel up" "front wheel down" "rear wheel up" "rear wheel down" boxes. If your actuators are getting an open signal those will change from off to on.
View attachment 1278722

@ihadmail if you are still around. I now have a 2006 model that needs AHC adjustment. I have the Techstream installed and running. Now I need to adjust it and was wondering if your offer to help was still on the table

 

[IceStorm]

Thanks for the update...you nailed it! Probably $600 repair in the US, assuming you could find someone capable of repairing it without telling you that you needed a new pump, shocks, ECU, accumulators....

When you get your Techstream up and running we will sort your neutral pressures out too. For info, Dorman make an aftermarket OE equivalent height sensor potentiometer (not the complete unit with bracket and short cable, just the actual potentiometer) it's the Dorman 924-755 Headlight Leveling Sensor that bolts straight in - $US 55 off Amazon.

@PADDO, I now have a 2006 that needs a little adjustment of the pressure and height. I have the Tech-stream up and running. If you are still on here and if you feel up to it I could use a little advice on the settings

 

[PADDO]

@PADDO, I now have a 2006 that needs a little adjustment of the pressure and height. I have the Tech-stream up and running. If you are still on here and if you feel up to it I could use a little advice on the settings

Sure, since you asked so nicely Take some hub center to fender bottom height measurements at each corner when parked on flat level ground, no junk in the rear (or if you’ve got extra weight permanently fitted give a rough outline of what is where) and do a L to N raise. Post a screen shot of the AHC data list page going from L to N with your actual measured heights and we will go from there.

 

[IceStorm]

Sure, since you asked so nicely Take some hub center to fender bottom height measurements at each corner when parked on flat level ground, no junk in the rear (or if you’ve got extra weight permanently fitted give a rough outline of what is where) and do a L to N raise. Post a screen shot of the AHC data list page going from L to N with your actual measured heights and we will go from there.

Thank you Paddo. Will do and will post here tomorrow.