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Code Y51/1 airmatic volume valve, loose connection after front strut replacement
Just Replaced the front left air strut over the weekend & now I'm getting a code Y51/1, loose connection/contact airmatic additional volume valve, after driving a few yards.
Which plug is this? There is one at the top of the strut & also a long pigtail plug at the bottom. Which contact should I be checking? The valve seemed to work, I used a 9v to deflate it before installation.
Assuming both plugs are good & secure, is there anything else I should check before removing the strut? It's a new strut & would rather avoid having uninstall it & send it back.
When I was looking rear bags for my car, Inoticed that one manufacturer recomended replacing both bags, as the resistance of the valve coil might differ enough to set a code.
So there may not be any actual problem, just different resistance, but then again, new part can be defective too. If you have a multimeter, check resistance from both.
I'll check the resistance.
Thankfully I still have the old strut. There wasn't anything wrong with it except age & mileage. I replaced the right side a few months ago due an air leak, figured I'd replace the left side also.
I opened the door, the suspension tried to auto level & I could hear a loud snapping / clicking coming from the left side strut hat. Didn't sound normal.
I did check the voltages, what a pita, here's what I got. I believe everything is in range but that snapping noise makes me suspect.
NEW OLD
Bottom / middle 11v. 11.2
Bottom / top. 3v. 3v
Middle / top. 8v. 9v
I also checked voltage with the icar scan tool & all the sensors I can access all appear to be within spec.
Everything appears to be within spec.
One thing I did notice is that the harness plug going into the strut hat isn't fully secured. The locking tab on the harness plug doesn't fully seat.
Almost like the shroud covering the contacts on the strut hat is slightly to long not allowing the harness plug to fully seat.
Tried a little die electric greese around the shroud but still won't fully seat. Might try and shave a little off the housing, see if that works
Last edited by Ken Keith; Jan 8, 2026 at 10:50 PM.
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