SwedeSpeed - Volvo Performance Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
758 Posts
Discussion Starter · #1 ·
I am getting this error message and the suspension seems to be stuck in the sport position.
I attempted a SUM calibration on I am getting
A rear right position sensor low voltage indication.
The rear left and all valves of the 4 dampers are all ok
Is this a rear position sensor?

This one is from a spare rear axle I have. The one on my car looks ok. Any one had this problem? Any advice?
 

·
Registered
Joined
·
8,062 Posts
Yes, that is your rear position sensor. If vida says its giving a bad reading and you are at the proper ride height it wouldn't be a bad idea to swap in your spare to see if it fixes the issue.
 

·
Registered
Joined
·
758 Posts
Discussion Starter · #3 ·
I replaced the sensor but that didn't solve the problem.
This is what I am getting

When I try to get SUM calibration

And when I read sensor data while not driving

I removed the SUM module and there are no apparent damages, but I believe I still need to replace it.
Any one has a spare SUM module to sale? I guess it has to a 2004 as this the year of my car.
 

·
Registered
Joined
·
290 Posts
Is your car lowered?
 

·
Registered
Joined
·
758 Posts
Discussion Starter · #5 ·
No it is not. Still on original springs. Also, the measured voltage of the rear right position sensor is 0 and not simply a value that would be too low because the car is lowered.
 

·
Registered
Joined
·
6,622 Posts
Continunity test from the SUM to the sensor? If that's even possible. Try moving the sensor to an extreme position and see if the value changes at all?
 

·
Registered
Joined
·
92 Posts
I just did the "bend the position sensor endlinks so the car is happy lowered" trick, and I know how much of a pain in the ass it is to get in there. If I was seeing what you are, I would be looking at shooting the wires from the position sensor to the SUM (as mentioned before). Especially since when you look at the values of sensor, even when it is moved to extreme positions or unplugged, Vida would show the refreshing voltage as 0.00 / 0.01 / 0.02 because it was showing some inductance from the wires. Another thing that I found while I was in there, that could be the problem, is my coil spring was crushing my 4c solenoid wire to the rear shock. The crush caused a short. If your sensor wire is shorted to itself, it will show a 0 for voltage since that seems to be how Vida displays over/under-range or over-load voltages.
 

·
Registered
Joined
·
182 Posts
The SUM has a couple different circuits that it uses for all the sensors. When the SUM sees voltage outside a normal range, like a short, it will shut down that circuit. So not only will the culprit go to 0V, so will many other sensors, like you are seeing in VIDA.

Since there is a code for the front left sensor, I would look into that. It might be the cause of faulting the same circuit of the rear sensor, meaning you can't calibrate.
 

·
Registered
Joined
·
174 Posts
When all else fails...

And when I read sensor data while not driving
See all those 0V readings? Unless you're the world's biggest coincidence theorist, that should tell you that the 5V supply to multiple sensors is, uh, offline, disabled. (The left rear has its own 5V feed; VIDA documents this; ...makes no sense to me why, but it sure makes diagnosing the problem, from this single image, easy...)

The good news is that the SUM's 2 5V power supplies are pretty well self-protected, and once you clear the (probably wiring) issue that is bringing it down/offline, that 5V feed will almost certainly resurrect itself.

Unless/until you correct the cause, you are wasting your time replacing (could just disconnect...) sensors and attempting recalibrations...
 

·
Registered
Joined
·
758 Posts
Discussion Starter · #11 ·
See all those 0V readings? Unless you're the world's biggest coincidence theorist, that should tell you that the 5V supply to multiple sensors is, uh, offline, disabled. (The left rear has its own 5V feed; VIDA documents this; ...makes no sense to me why, but it sure makes diagnosing the problem, from this single image, easy...)

The good news is that the SUM's 2 5V power supplies are pretty well self-protected, and once you clear the (probably wiring) issue that is bringing it down/offline, that 5V feed will almost certainly resurrect itself.

Unless/until you correct the cause, you are wasting your time replacing (could just disconnect...) sensors and attempting recalibrations...
Thanks a lot for the insight. How do you the find this kind of documentation on vida?
 

·
Registered
Joined
·
758 Posts
Discussion Starter · #12 ·
The problem was indeed a frayed wire from the front left acceleration sensor. It came loose and had been rubbing against the drive shaft and was worn in 2 different places. Once I repaired the wire and did a SUM calibration, everything went back to normal.
 

·
Registered
Joined
·
14 Posts
I got the same problem with the front left sensor.

As far as I know the sensors are connected with each other, so if one sensor stops working or has a short circuit, the sensors won't be in a closed loop, so it shows no voltage for any of them.
 
1 - 17 of 17 Posts
Top