Air Suspension Level sensor info req
07-03-2014, 10:13 PM
#1
Racer
Thread Starter
Air Suspension Level sensor info req
Can anyone give me more info on these sensors? My understanding is that they are a contactless (hall effect) type sensor made by Hella using their CIPOS technology.
AFAIK these sensors come in two flavors . PWM and analogue. The anolgue one i am assuming will act just like an old fashioned variable resistor and output a voltage ? The actual values screen shows all my sensors at about 2.4v approx (at normal ride height) apart from my FL sensor which show 0V. If i swap the FL and plug it into the FR sensor plug, that one goes to OV. Plug the FR sensor back in and the FR sensor goes back up to 2.4v. I have also connected the sensor up to 5v and Gnd and have 4.5v on the output pin (assuming i got the pins correct ! ) with the sensor disconnected(i am assuming the pin "floats" and thats why it doesn't show on the actual reading. My conclusion being I have a faulty FL sensor .
Am i correct or am i missing something obvious? Are the sensors analogue out or Pulse width Mod output? What is the correct pin assignment?
This is on an 04 Cayenne S
edited with more info on volt meter reading
AFAIK these sensors come in two flavors . PWM and analogue. The anolgue one i am assuming will act just like an old fashioned variable resistor and output a voltage ? The actual values screen shows all my sensors at about 2.4v approx (at normal ride height) apart from my FL sensor which show 0V. If i swap the FL and plug it into the FR sensor plug, that one goes to OV. Plug the FR sensor back in and the FR sensor goes back up to 2.4v. I have also connected the sensor up to 5v and Gnd and have 4.5v on the output pin (assuming i got the pins correct ! ) with the sensor disconnected(i am assuming the pin "floats" and thats why it doesn't show on the actual reading. My conclusion being I have a faulty FL sensor .
Am i correct or am i missing something obvious? Are the sensors analogue out or Pulse width Mod output? What is the correct pin assignment?
This is on an 04 Cayenne S
edited with more info on volt meter reading
Last edited by Laurence Gibbs; 07-07-2014 at 08:25 AM.
07-07-2014, 06:11 AM
#3
Racer
Thread Starter
Thanks
problem with going to VW is knowing which model and version it comes off. I can quote the number off the switch There are several versions of this switch and the level controller. So when you ask them the first thing they say is what model year , chassis number. Which you can't answer. By the wealth of answers to my questions on here. Not many people know much about these sensors outside the dealers.
just rang my opc, they want £168 for one
problem with going to VW is knowing which model and version it comes off. I can quote the number off the switch There are several versions of this switch and the level controller. So when you ask them the first thing they say is what model year , chassis number. Which you can't answer. By the wealth of answers to my questions on here. Not many people know much about these sensors outside the dealers.
just rang my opc, they want £168 for one
07-31-2014, 08:33 PM
#6
Racer
Thread Starter
Just to update this thread. My level sensor was indeed faulty. I managed to source a replacement from a Touareg . There appears to be a few different part numbers for these sensors . It took a while and a bit of luck to get one that matched. My car has Xenons which are possibly a different part number to other level sensors. Mine had TZ2 at the end of the part number, i saw many with TZ1 !
The sensors use Pulse width Modualtion and can be scoped to see the waveform. The sensors measure angle , so i would be careful about swapping out sensors with different paart numbers as the angles measured could be different. Some sensors create two outputs , one for the air suspension and one for headlight beam Alignment / dynamic levelling .
For faulting, check the controller & the loom for shorts etc and the lug and socket of the sensor for high resistance. Use the Actual values screen (PST2 or durametric etc) to see what sensor values you have . mine showed 0V for the Front left sensor and if i swapped the sensor to Front right the fault moved. If your symptoms are the same , most likely youe sensor has failed.
You will need to calibrate the level controller after the sensor is fitted as the stored value will not match for the new sensor.
The sensors use Pulse width Modualtion and can be scoped to see the waveform. The sensors measure angle , so i would be careful about swapping out sensors with different paart numbers as the angles measured could be different. Some sensors create two outputs , one for the air suspension and one for headlight beam Alignment / dynamic levelling .
For faulting, check the controller & the loom for shorts etc and the lug and socket of the sensor for high resistance. Use the Actual values screen (PST2 or durametric etc) to see what sensor values you have . mine showed 0V for the Front left sensor and if i swapped the sensor to Front right the fault moved. If your symptoms are the same , most likely youe sensor has failed.
You will need to calibrate the level controller after the sensor is fitted as the stored value will not match for the new sensor.
