Hi All,
Ryan did a sterling job installing my SG6, but I decided it was time for a spring clean when I got her home and I started cleaning out a lot of old wiring. I've disturbed the abs feeds though whist working (did try and take care) and the ecu is throwing up a warning.
Opening Smon I can find flspeedv for all 4 wheels bar the front left, so thinking this may be the problem and need to check.
I have 2 questions...
- how do I determine which pin has been used for the abs feeds?
- and in vehicle speed of Smon what is the difference between rl/fl/rr/frspeed and rl/fl/rr/frspeedv?
One if my rear sensors shows an rlspeedv value but no rlspeed value...
The front left shows no value for either..
Help would be appreciated before I dig further...
Kind regards
Mike
newbie question on ABS feeds and softwear interpretation
Re: newbie question on ABS feeds and softwear interpretation
anything suffixed with "v" is the voltage on that channel, the non suffixed parameter is the final output of the sensor, whether that be a speed, pressure, temperature or percentage.
To figure out what goes where, you need to use scal and go to IO configuration->pin assignements and there you will find the wheel speed inputs.
You should look at the voltages to figure out connectivity issues. You may not generate a useable speed value until you have enough pulses or speed enough to create a voltage so don't panic yet, many sensors are speed dependant.
Use a "trace" gauge at 50 or 100hz to look at subtle or fast changes in voltage.
To figure out what goes where, you need to use scal and go to IO configuration->pin assignements and there you will find the wheel speed inputs.
You should look at the voltages to figure out connectivity issues. You may not generate a useable speed value until you have enough pulses or speed enough to create a voltage so don't panic yet, many sensors are speed dependant.
Use a "trace" gauge at 50 or 100hz to look at subtle or fast changes in voltage.
Re: newbie question on ABS feeds and softwear interpretation
Thanks For that..
Ryan did say that he may have wired it up with both fronts on one input, but softwear suggests different as there is a listing for flspeed and flspeedv, as well as fr speed and frspeedv and I am getting abs lights on the dash...
also the fact that one of the rear sensors is not returning a non prefixed return is concerning..
I'll keep digging..
Ryan did say that he may have wired it up with both fronts on one input, but softwear suggests different as there is a listing for flspeed and flspeedv, as well as fr speed and frspeedv and I am getting abs lights on the dash...
also the fact that one of the rear sensors is not returning a non prefixed return is concerning..
I'll keep digging..
Re: newbie question on ABS feeds and softwear interpretation
So your rlspeed is not working, is that correct?
If you've got 2 wire reluctor sensors (likely) then the voltage will be centered around 2.5 volts most likely, and when the sensor is working it will go up and down around that. So just because you have "a voltage" it doesn't mean there isn't a wiring problem. If the sensor is a hall effect then it may be stuck at 5v (or very close) if it's not working.
Find what you disturbed, fix it! Start looking at the input for the sensor, if the ABS light is on, then the sensor wiring bust either be borked between the sensor and the ABS module, OR the wiring is shorted at the ECU end.
If you've got 2 wire reluctor sensors (likely) then the voltage will be centered around 2.5 volts most likely, and when the sensor is working it will go up and down around that. So just because you have "a voltage" it doesn't mean there isn't a wiring problem. If the sensor is a hall effect then it may be stuck at 5v (or very close) if it's not working.
Find what you disturbed, fix it! Start looking at the input for the sensor, if the ABS light is on, then the sensor wiring bust either be borked between the sensor and the ABS module, OR the wiring is shorted at the ECU end.
Re: newbie question on ABS feeds and softwear interpretation
Yup, rrspeed - shows voltage on rrspeedv, but against rrspeed it returns a zero when the car is rolling and the frspeed and rlspeed is... see pic below (whilst car was pottering in 2nd gear.pavlo wrote:So your rlspeed is not working, is that correct?
- Screen Shot 2012-05-23 at 15.00.23.png (21.48 KiB) Viewed 17921 times
these are the pin assignments for your info...
as suspected the fr was wired in only, fl is not, hence negative values for fl...
- Screen Shot 2012-05-23 at 14.50.30.png (13.61 KiB) Viewed 17928 times
Re: newbie question on ABS feeds and softwear interpretation
The front sensor is on a thermistor input, and I suspect may be connector via a reluctor sensor level converter.
However, it is not enough to look at the a snapshot of an instant in time, you need to either use trace gauges to see the waveform, or log the channel at say 1000hz for short time and look at the results, you will need to use SCfg to config some alternative logging temporarily and Sview to look at the logs. If you can't do those things then you really need to think about getting an expert in to do it for you, or learn quickly how to do it.
You need to appreciate that the wheel speed sensors are giving pulses or some other waveform, not a voltage that only varies with wheelspeed.
But as I have already said, you need to look at what you've done, look for for broken wires, shorted wires, contacts not fully home etc. It worked, you did some stuff, now it it doesn't work, 99.99% of the time that means you done fucked it up! Retrace your steps.
However, it is not enough to look at the a snapshot of an instant in time, you need to either use trace gauges to see the waveform, or log the channel at say 1000hz for short time and look at the results, you will need to use SCfg to config some alternative logging temporarily and Sview to look at the logs. If you can't do those things then you really need to think about getting an expert in to do it for you, or learn quickly how to do it.
You need to appreciate that the wheel speed sensors are giving pulses or some other waveform, not a voltage that only varies with wheelspeed.
But as I have already said, you need to look at what you've done, look for for broken wires, shorted wires, contacts not fully home etc. It worked, you did some stuff, now it it doesn't work, 99.99% of the time that means you done fucked it up! Retrace your steps.
Re: newbie question on ABS feeds and softwear interpretation
Have you changed ANYTHING in the sensors menu?
It looks like the rr sensor is configured as a thermistor input rather than a bipolar given that the voltage seems to be a static 4.961.
It looks like the rr sensor is configured as a thermistor input rather than a bipolar given that the voltage seems to be a static 4.961.
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pat
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Re: newbie question on ABS feeds and softwear interpretation
Gents,
AB04 is not capable of Thermistor operation, BUT it does have a bias pull up and divider which takes the -5V / +5V range and turns it into 0V / 5V for the analogue to digital conversion. If the sensor goes open circuit then the bias resistor, although much weaker than a thermistor pull up, will be the "strongest" element and send the voltage up to +5V. Also note that the anXXV values are not scaled, so AB4 should be sat at 2.5V when there is no signal, although rrSpeedV may / should read zero.
Hope this helps,
Pat.
AB04 is not capable of Thermistor operation, BUT it does have a bias pull up and divider which takes the -5V / +5V range and turns it into 0V / 5V for the analogue to digital conversion. If the sensor goes open circuit then the bias resistor, although much weaker than a thermistor pull up, will be the "strongest" element and send the voltage up to +5V. Also note that the anXXV values are not scaled, so AB4 should be sat at 2.5V when there is no signal, although rrSpeedV may / should read zero.
Hope this helps,
Pat.