Late edit: Pics attached at end of post.
I feel your pain!!
Great descriptions in your posts. If I have understood correctly, the observed symptoms are summarised below. Of these,
the most troubling is Item 10 in the list below – because it means that power is not going where needed for operation of the AHC/TEMS system.
1. All four ‘globes’ have been replaced recently,
2. AHC “Off” light blinks,
3. AHC
does not respond to AHC “On/Off” switch on centre console,
4. AHC
does not respond to “Up/Down” rocker switch on centre console – does not raise or lower,
5. AHC system has been bled multiple times (??).
[Notes: Description at Posts at #324 and #339 says: “…. turning on the vehicle to let it adjust height, then bled all the valves to get the air bubbles out”. This may not be enough – better to drop to “LO” them bleed – but it seems that the vehicle will not raise or lower? If it has not been possible to use a method such as the @PADDO method -- https://forum.ih8mud.com/threads/replacing-ahc-globes-accumulators.716383/#post-11432901 --
then there is a very high risk of air still in the system, especially after a ‘globe’ change. There are quite a few Posts on IH8MUD where Members have struggled to get rid of remnant ‘plugs’ of air in the system – frustrations eventually solved by repeating the recommended method – but necessary to raise and lower multiple times],
6. Techstream was not used, not available to Owner, Fort Collins 4x4 recommends “go a to a Dealer”
[Notes: More frustrations and again I feel your pain -- can a Dealer or other workshop be found with Technicians willing and able to interpret physical symptoms and Techstream readout, not just plug in the scanner?!],
7. On start-up, vehicle
does auto-level as expected. This may mean that AHC Pump and the Height Control Accumulator (long cylinder on LHS chassis rail) actually is working?
[Notes: Need to check by listening/feeling at Pump and Accumulator pipes when vehicle is auto-levelling],
8. Fuses checked?
[Notes: Which fuses? Have all AHC fuses and relays been located?]
9. Attempted re-set – disconnected/reconnected battery – then found Front raises but not the Rear.
[Notes: If not already done, also suggest further re-set attempt by pulling AHC IG fuse behind LH cover on LH footwell, inspecting, resting, replace for certainty -- then re-inserting fuse – see pic below]
10. AHC Height Control Operation Test (a.k.a. “Active Test”) does not work per posts #327 and #334 in this thread.
Notes: This is very unusual.
In this test, be sure engine is running, not just ignition “ON”.
If “Active Test” does not work, it means either
(i) something simple – like faulty console switches. Suggest check/clean console switches per Suspension problem even after replacing almost everything - https://forum.ih8mud.com/threads/suspension-problem-even-after-replacing-almost-everything.812905/page-2#post-9444024, then suggest follow the whole “Pre-Check” procedure set out in the attachment to my Post #327 in the current thread. This does not require Techstream,
OR,
(ii) pump is blocked (can happen) or motor is faulty (unusual) or power is not arriving at the AHC Pump. Suggest check operation of AHC Pump and Motor: pull plug from the Motor, apply power to Motor using leads from 12 volt battery directly to the motor terminals. This does not require Techstream,
OR,
(iii) if pump operates by direct connection to battery but not in ordinary operation nor in “Active Test”, it means power is not getting to the Pump and the AHC system. By inspection and with a multimeter (Techstream is not required):
- check AHC- B Fuse and AHC IG Fuse in Left Hand Side kickpanel in the driver’s footwell, and,
- using FSM instructions, test the AHC Main Relay located at or near the Electronic Control Unit (ECU) under the dashboard on the upper Right Hand Side of the driver’s footwell.
For the above items, see guidance and FSM extracts scattered in Posts #41 and onwards at this link:
Quick question about AHC ride with extra weight - https://forum.ih8mud.com/threads/quick-question-about-ahc-ride-with-extra-weight.1247828/page-3#post-13957466
including Posts #71 and #76 in that thread for pictures of possible different fuse panel layouts.
With the above observations in mind, may I also suggest that it is worth going back yet again to the FSM "Diagnostics" section:
https://lc100e.github.io/manual/
At this link, use the Index on the left hand side of the opening page and follow these tabs:
Repair Manual > DIAGNOSTICS > ACTIVE HEIGHT CONTROL & SKYHOOK TEMS
Before getting into all the detail, the FSM outlines at the start this section a diagnostic process. Among other things, this explains situations in which Diagnostic Trouble Codes (DTC's) may not be recorded even when faults or 'difficulties' exist.
The upshot is that Techstream is an extremely helpful tool, no doubt about that, and the presence of a DTC
may help to identify and fix a problem (and usually does).
However, the reverse is not true – the absence of DTC’s
does not guarantee that all is well.
The point is that investigation by observing symptoms and by being handy with a multimeter, considerable progress can be made.
At the above FSM reference, “Terminals of ECU” (FSM Page DI-248) provides a way of doing ‘health checks’ at the terminals of the ECU.
The diagnostic adventures of
@YvesNL can be seen at the next link and may provide some insights:
Hi From The Netherlands & AHC Issues - https://forum.ih8mud.com/threads/hi-from-the-netherlands-ahc-issues.997849/page-3
Hope that somewhere in all this information, there might be a helpful starting point!
Two variants of LHS Footwell Electrical Panels:
View attachment 2738966
View attachment 2738968