Well, at this point I’ve gone though just about everything on the AHC system trying to chase down an issue that I can’t see. A couple weeks ago I had a rear axle overload issue, and it dropped into low (basically on the bump stops) and started flashing the AHC off light.
On TechStream I am not able to read any of the AHC related DTC’s, getting an error code every time I attempt to read the trouble codes.
At this point I have added non-AHC springs with airbags in the rear to help with the heavy weight, and now it is driveable, but not handling well, and also not able to go into High or even Neutral.
So in an attempt to get the AHC functioning again without being able to see the codes, I’ve replaced the AHC ECU with a known good unit, the height control switch (on the center stack), all related mini fuses, swapped and tested relays, got a new main AHC relay (also tested), known good rear height sensor, made sure sensors were all reading within .5inches of one another, taken most of the weight off of the system with jacks, checked main valve body connectors on the drivers frame rail, and last but not least tested the pump to make sure it functions.
The only thing in all of that that did give me cause for suspicion was when I was testing the pump, it turned on with JUST power to the positive post on the plug, the negative post wasn’t hooked up to anything. Is that cause to deem the pump dead?
I’m getting pretty annoyed at this point, but we’ve got a trip we were suppose to leave on about an hour ago, so gotta get this thing done. Thank you all for your help!
On TechStream I am not able to read any of the AHC related DTC’s, getting an error code every time I attempt to read the trouble codes.
At this point I have added non-AHC springs with airbags in the rear to help with the heavy weight, and now it is driveable, but not handling well, and also not able to go into High or even Neutral.
So in an attempt to get the AHC functioning again without being able to see the codes, I’ve replaced the AHC ECU with a known good unit, the height control switch (on the center stack), all related mini fuses, swapped and tested relays, got a new main AHC relay (also tested), known good rear height sensor, made sure sensors were all reading within .5inches of one another, taken most of the weight off of the system with jacks, checked main valve body connectors on the drivers frame rail, and last but not least tested the pump to make sure it functions.
The only thing in all of that that did give me cause for suspicion was when I was testing the pump, it turned on with JUST power to the positive post on the plug, the negative post wasn’t hooked up to anything. Is that cause to deem the pump dead?
I’m getting pretty annoyed at this point, but we’ve got a trip we were suppose to leave on about an hour ago, so gotta get this thing done. Thank you all for your help!