PLEASE HELP AHC pogo stick (1 Viewer)

[Stricmic000]

ill get right down to it, in N and L mode the rear of my lx is like a pogo stick, front works perfect, in H mode front and rear both work perfectly....Globes are good and fluid is good and has been bleed, pressures are all good in H mode but in L and N the rear pressure goes up to 7+ but is only 6.4 in H mode I just replaced the rear height sensor and nothing changed.

 

[BEG]

Bump for @PADDO or @uHu to chime in. Something weird happening with those pressures. Possibly the accumulator locking itself out for some reason.

 

[OEMGUY0720]

Do you have Techstream? That’s your best source of information if the pressures are changing when setting it to L or N or H.

 

[Stricmic000]

I am using OBLink and it is showing me information...but not the reason that the rear is locking out, when doing the 16 step damping test it shows that while in both H N and L mode the damping starts in level 1. in H that is correct but as soon as i go to N or L (meaning that i choose N mode shut the door and run to the corner and bounce the bumper it is already locked out before it even moves) it locks out the rear but still shows being in step 1 on both front and rear

 

[BEG]

I am using OBLink and it is showing me information...but not the reason that the rear is locking out, when doing the 16 step damping test it shows that while in both H N and L mode the damping starts in level 1. in H that is correct but as soon as i go to N or L (meaning that i choose N mode shut the door and run to the corner and bounce the bumper it is already locked out before it even moves) it locks out the rear but still shows being in step 1 on both front and rear

Could be that the 4-position switches at the damper accumulator/ globe assemblies need cleaning and are not cycling the stepper motors through their positions. (PADDO's pic)

 

[Stricmic000]

I will pull this switch off after I get home!

 

[Stricmic000]

Switch looks great and according to obdlink it is getting the correct readings

 

[Stricmic000]

Im gonna unplug the rear height sensor and see what changes, might have a damaged wire someplace thats used for n N and L mode

 

[BEG]

Keep us posted. I'm interested in finding out what the issue is.

 

[Stricmic000]

looks like the wiring harness is very concealed but im not getting any dct or check engine lights so idk if it could be bad but its worth a shot to trace the wires or test them

 

[uHu]

Not much to contribute here, but some ramblings...

You talk about pressures at all 3 height settings - Have you measured that with pressure gauges?
The TechStream or obdLink cannot tell you actual pressure in the spheres, as the system doesn't have any pressure sensors other than the one at the pump. The system is made so that if you move from Lo to N, it will compute the pressure at the exact moment when the front level valve closes, and then the rear level valve, and then the accumulator.
So, to measure the pressure, you have to have the heights right (physical, not obd readings), at both Lo and N; and also the obd height readings right; and then, with an empty car, move from Lo to N. That's it, the only pressure reading that means anything without attaching actual gauges to the bleeder holes.

Also the graduation test for the state of the spheres requires that heights, weight and pressures are within specs, and no air bags. It is also possible to have one punctured sphere and 3 good ones, and still get a 75% good reading.

And on dtc's: the ahc system is not good at reporting helpful codes. You really just have to physically check all the basics of sensors, linkages, connectors, valves, and so on.

 

[Stricmic000]

For sure, I've never measured the pressures outside what the computer tells me but before this happened my cross level front height and rear Heights and pressures were all good using a tape measure and an OBDlink, my ride height is still correct via tape measure...but not sure why the rear is locking out, when I have time I'm going to try and follow the wires and check all the connections

 

[Stricmic000]

My graduations are 14 marks with 2k miles on paladies spheres, the part that confuses me the most is that when I am in H mode everything works perfectly. The moment I select a Neutral even before the car starts moving the backend locks out the damping

 

[l3n0x]

What numbers do your height sensors read exactly in normal height? Let us know

 

[Stricmic000]

This is now, before it was the same but rear pressure was closer to 6.2

 

[l3n0x]

these numbers do look fine:/

 

[Stricmic000]

ok, traced wires and was able to see about 50% of the entire loom and was able to find all the connectors and do a visual inspection (some are very hard to reach) under the truck using a mirror and a light and it looks great, no signs of exhaust leak anywhere that would cause melted wiring... i guess i can move on to learning how to and then testing the wiring harness......anyone know what would cause the damping to go into safe mode on LR and RR corners at the same time?

 

[Stricmic000]

MY06LX EWD needed badly

If anyone has a link to it?, ... need to trace AHC ECU harness from ECU connectors to damping force actuators, and the connectors at ECU are not marked ... need back of AHC ECU connector view. Thx!

forum.ih8mud.com

im going to copy this thread and test wiring looms, never done it so any advise would be appreaciated, gonna ground one end of a harness and test resistance on all pins then move the ground to the next pin...and repeat

 

[Stricmic000]

This is a super cool AHC Diagram, I only see one wiring set that shares both rear damping actuators so I think that's where my problem probably is because they both act the same and stop working at the same time

 

[Stricmic000]

I stole these from @PADDO but ill post em cause they are helping me and if your searching this will help you too