I need a second third and possibly a forth opinion on this problem. i cannot figure it out to save my life. first i will say that i have replaced the pump,dryer and both front bags.no solenoids or sensors.in normal driving conditions with the air ride on it rides fine but when the car lowers at 55 mph it happens. it seems that only the front lowers while the rear stays at normal ride height. when i exit the highway and the vehicle pumps back up the front pumps to normal ride height but the rear never vented so it pumps up to twice the normal ride height.the strange thing is i am almost positive that the front drops and vents into the rear bags even when the air ride is off.if this is not possible than maybe only the front vent when the air ride is off.is it the computer? is it the solenoids? maybe the sensors?.. at this point i cannot say. any help would be great...
suspension leveling issue......
- Thread starter 94Panther
- Start date
sleeper
Former LOD President
RE: suspension leveling issue......
Something is clogged somewhere. Either one of the lines going baok to the rear, your vent solenoid, or (most likely) the solenoids on your rear bags. The vent solenoid should have been replaced when you did the compressor. If the front is venting into the back, though, that would normally lead me to say vent solenoid. Go around and check all the sensors though, make sure they're all hooked up properly. Do you get a check air ride message at all?
Something is clogged somewhere. Either one of the lines going baok to the rear, your vent solenoid, or (most likely) the solenoids on your rear bags. The vent solenoid should have been replaced when you did the compressor. If the front is venting into the back, though, that would normally lead me to say vent solenoid. Go around and check all the sensors though, make sure they're all hooked up properly. Do you get a check air ride message at all?
RE: suspension leveling issue......
First of all, nothing should happen when the car's air ride switch is off. So, if something is happening to your car when it is off there is a major problem with the system. If it moves with the switch off, either the switch is not working correctly or the module is bad. Do you get the message that the air ride switch is off in the message center when it is? Check that. If not, it's probably the switch or wiring. You should always keep it on (in the up position) while driving with no indication in the message center.
But, it does sound like the vent solenoid is not opening up when you increase speed, however, it does after you get out of the car. When you get out of the car, first, you trigger the air ride system to do nothing, because the system is designed NOT to vent when a door is opened and the car is not moving. That way, the door will not drop and hit a curb while open, etc. Once you close the door, the system senses that, and then a "trim high" signal is sent from the three sensors to the module and it adjusts the car for up to an hour after the door is shut. In order for the front springs to vent into the back, ALL spring solenoids have to open, which is normal when INCREASING Speed, but the vent solenoid would have to stay shut. But, to operate correctly, the vent solenoid has to open too. However, it does when you get out of the car. Try this first:
After going over 55 mph and you are having the problem, try turning the inside dome light on, then off after you've stopped using the panel dimming control. This would simulate a door opening and closing. (or if stopped, open and close the door). See if the car trims out properly then. If it does, it's probably the module.
If you want to try to fix it yourself, or just to see what is happening to the solenoids, you could gain access to your Air Suspension Module. It is in the right kick panel where the passenger's feet are. Using a small 12 volt bulb (and I mean small) Ground one side of the bulb to a known good ground, and then use a small pin (like a sewing pin, not needle) to penetrate through the following wires and clip a connection to the other side of the bulb:
On the Black Connector on the module:
Pin 30 (Pink wire) The Vent Solenoid control.
Pin 18 (Dark Blue/Yellow wire) if you want to monitor the compressor on/off.
On the Gray connector on the module:
Pin 14 (Light Green/ Orange wire), The LF Air Spring Solenoid Output.
Pin 15 (Orange/Red wire) The RF Air Spring Solenoid Output.
Pin 16 (Purple/Light Green wire) The LR Air SpringSolenoid Output.
Pin 17 (Light Blue/Black wire) The RR Air Spring Solenoid Output.
Check each one individually by connecting the ground wire to one side of the small lamp. Try the vent solenoid control first along with the compressor if you want. Just push the small pin through the middle of each wire (use leather gloves) and clip the other side of the lamp to it. Have someone else drive on the highway and you see if the lamp lights indicating that it opens up the connected solenoid to vent or fill and then what happens when you go over 55 and then stop. Then try another solenoid. You could also use six lamps. and use a numbering system (V for vent, C for compressor, then LF, LR, RF, RR for each of the four other solenoids). Be sure to insulate the connections if you use all of them at once. Then have someone else drive and you watch them over at the co-pilot's seat when you are testing. Make sure the car has enough time to lower when going over 55 mph. When the bulb lights, the solenoid is getting power. The fact that the car settles to the correct height when you exit, shows that the spring solenoids are working and venting properly, including the vent solenoid. Be sure the door open warning is not on. The open door will not stop any action by the module if it shows the door open and the vehicle is going at least 5 mph. It ignores the signal when you are moving, but not when stopped.
If the solenoids are not working properly (lamps are not going on at the correct time), the module is probably bad.
From a stand still, air switch on, car at rest and at proper height:
Once you get into the car (with or without a passenger) the car should trim up. That means:
1. All spring solenoids should open. The vent solenoid should not.
2. The compressor should run.
3. As each wheel's sensor is satisfied, the solenoids should shut off independently.
4. When the last wheel's solenoid turns off, the compressor turns off.
5. The vehicle should be at normal trim height again.
Now for the test:
1. Accelerate to just past 55 mph.
2. All five solenoids should open to vent.
3. The compressor should not run.
4. Each spring solenoid should close when the car lowers and the sensors tell it to stop venting each spring. (Remember the rear has only one sensor. There are two in the front).
5. The vent solenoid should close with the last wheel's solenoid.
6. The car should be in crrrruuuuuise mode.
When you slow down or stop:
1. All spring solenoids should open.
2. The compressor should run. (you can hear that)
3. The vent solenoid should stay closed.
4. When each wheel is pumped up to "trim height" the solenoid should close. (It should turn off the solenoid to that specific wheel).
5. When the last wheel is satisfied, the compressor should turn off.
5. Vehicle should be at the correct height.
Remember when the light is on, the solenoid is OPEN.
If it does not happen like this, there is a more serious problem, probably either the speed sensor (which I doubt, because it knows when you've exceeded 55 mph) or the module is bad.
First of all, nothing should happen when the car's air ride switch is off. So, if something is happening to your car when it is off there is a major problem with the system. If it moves with the switch off, either the switch is not working correctly or the module is bad. Do you get the message that the air ride switch is off in the message center when it is? Check that. If not, it's probably the switch or wiring. You should always keep it on (in the up position) while driving with no indication in the message center.
But, it does sound like the vent solenoid is not opening up when you increase speed, however, it does after you get out of the car. When you get out of the car, first, you trigger the air ride system to do nothing, because the system is designed NOT to vent when a door is opened and the car is not moving. That way, the door will not drop and hit a curb while open, etc. Once you close the door, the system senses that, and then a "trim high" signal is sent from the three sensors to the module and it adjusts the car for up to an hour after the door is shut. In order for the front springs to vent into the back, ALL spring solenoids have to open, which is normal when INCREASING Speed, but the vent solenoid would have to stay shut. But, to operate correctly, the vent solenoid has to open too. However, it does when you get out of the car. Try this first:
After going over 55 mph and you are having the problem, try turning the inside dome light on, then off after you've stopped using the panel dimming control. This would simulate a door opening and closing. (or if stopped, open and close the door). See if the car trims out properly then. If it does, it's probably the module.
If you want to try to fix it yourself, or just to see what is happening to the solenoids, you could gain access to your Air Suspension Module. It is in the right kick panel where the passenger's feet are. Using a small 12 volt bulb (and I mean small) Ground one side of the bulb to a known good ground, and then use a small pin (like a sewing pin, not needle) to penetrate through the following wires and clip a connection to the other side of the bulb:
On the Black Connector on the module:
Pin 30 (Pink wire) The Vent Solenoid control.
Pin 18 (Dark Blue/Yellow wire) if you want to monitor the compressor on/off.
On the Gray connector on the module:
Pin 14 (Light Green/ Orange wire), The LF Air Spring Solenoid Output.
Pin 15 (Orange/Red wire) The RF Air Spring Solenoid Output.
Pin 16 (Purple/Light Green wire) The LR Air SpringSolenoid Output.
Pin 17 (Light Blue/Black wire) The RR Air Spring Solenoid Output.
Check each one individually by connecting the ground wire to one side of the small lamp. Try the vent solenoid control first along with the compressor if you want. Just push the small pin through the middle of each wire (use leather gloves) and clip the other side of the lamp to it. Have someone else drive on the highway and you see if the lamp lights indicating that it opens up the connected solenoid to vent or fill and then what happens when you go over 55 and then stop. Then try another solenoid. You could also use six lamps. and use a numbering system (V for vent, C for compressor, then LF, LR, RF, RR for each of the four other solenoids). Be sure to insulate the connections if you use all of them at once. Then have someone else drive and you watch them over at the co-pilot's seat when you are testing. Make sure the car has enough time to lower when going over 55 mph. When the bulb lights, the solenoid is getting power. The fact that the car settles to the correct height when you exit, shows that the spring solenoids are working and venting properly, including the vent solenoid. Be sure the door open warning is not on. The open door will not stop any action by the module if it shows the door open and the vehicle is going at least 5 mph. It ignores the signal when you are moving, but not when stopped.
If the solenoids are not working properly (lamps are not going on at the correct time), the module is probably bad.
From a stand still, air switch on, car at rest and at proper height:
Once you get into the car (with or without a passenger) the car should trim up. That means:
1. All spring solenoids should open. The vent solenoid should not.
2. The compressor should run.
3. As each wheel's sensor is satisfied, the solenoids should shut off independently.
4. When the last wheel's solenoid turns off, the compressor turns off.
5. The vehicle should be at normal trim height again.
Now for the test:
1. Accelerate to just past 55 mph.
2. All five solenoids should open to vent.
3. The compressor should not run.
4. Each spring solenoid should close when the car lowers and the sensors tell it to stop venting each spring. (Remember the rear has only one sensor. There are two in the front).
5. The vent solenoid should close with the last wheel's solenoid.
6. The car should be in crrrruuuuuise mode.
When you slow down or stop:
1. All spring solenoids should open.
2. The compressor should run. (you can hear that)
3. The vent solenoid should stay closed.
4. When each wheel is pumped up to "trim height" the solenoid should close. (It should turn off the solenoid to that specific wheel).
5. When the last wheel is satisfied, the compressor should turn off.
5. Vehicle should be at the correct height.
Remember when the light is on, the solenoid is OPEN.
If it does not happen like this, there is a more serious problem, probably either the speed sensor (which I doubt, because it knows when you've exceeded 55 mph) or the module is bad.