jonnyboy54321
Member Since: 14 Jul 2012
Location: surrey
Posts: 121
  
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| Diagnosing air suspension |
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Hi all.
Been doing quite a complex body-off project which took on arms and legs, lots of wiring loom disturbance, dash out etc. 2015 d4 commercial. Car has been in an accident.
Air suspension worked perfectly before body off. Chassis was stored with the suspension at normal ride height, no air suspension lines dismantled/disturbed.
No work done to chassis other than inlet manifolds and cam/fuel pump belts/new rad and front crash bar.
Built all back up, started up (have an odd charging system fault to work through), suspension fault. Have been checking and rechecking the loom connections etc. I had previously repaired a broken loom wire from the big nsr wheelarch area multiplug while the body was off - I presume it had been scarred as we lifted and jiggled the body but continuity-tested my repair and it seemed okay.
Rear suspension works perfectly, up/down all heights, level sensor readings changing on the GAP IID. The front, however, is unresponsive and it goes into "suspension fault".
Tried several times to re-enable eas, it tries to work, compressor fires up, rear does its thing but the front doesnt.
Fault codes registered are:-
C1A31-01 Front left corner valve general electrical failure
C1A32-01 Front right corner valve general electrical failure
C1A35-01 Reservoir valve - general electrical failure
Front corners are reading at around -65/-70 on the GAP, they flicker maybe one point when the compressor fires up. rears are currently at around 0 ish. I have independently jacked the nsf and osf body and the level sensors are altering reading nicely - as if they work as they did and are connected into the system. Have checked that the plug to the front crash bar valve block is properly connected, it is. Same with the larg multiplug above the o/s headlight under the top of the slam panel (i understand it carries suspension loom + others). I then replaced the valve block at the front with one off my other d4, no change. Can't hear any hissing anywhere. Have double checked all earths are connected, bright metal, and tight, they are.
At a bit of a loss - and could do with any work through pointers as I haven't yet had the pleasure of a significant suspension issue on a d4. My gut is that it's a loom/electrical issue but narrowing it down (poss via GAP) would be useful. Quite a coincidence that it has this charging system fault too which wasn't present before body off (charges at 13.5v according to GAP), bit of a coincidence, I recondition-charged both batteries while it was in bits, main battery is almost new (but pre-existing).
Thanks, sorry for long post.
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 22nd Aug 2024 8:47 am |
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Bleachi
Member Since: 10 Sep 2024
Location: Warsaw
Posts: 1
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Hi have you find propblem?
I have the same fault codes. Front suspension is riseing verry slowly.
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| 10th Sep 2024 1:02 pm |
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jonnyboy54321
Member Since: 14 Jul 2012
Location: surrey
Posts: 121
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My front suspension was inoperative. Found that one of the multiplugs on the air suspension module on the offside a pillar was slightly dislodged.
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| 10th Sep 2024 4:29 pm |
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