2008 VW T5 ABS speed sensor maximum value

   #1  

covex

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I come to one thing I do not understand - during testing of the ABS speed sensors on VW T5 (this is 7H0-907-37x.lbl file) I came to that the maximum speed it is able to show is cca 48km/h (the lbl reads 0.0..255.0km/h). The reading is consistent across all 4 wheels and up to that maximum matches the tacho. There is slight variance in the values the sensors give for different wheels but remains in the range of 4km/h (i.e. the lowest value is e.g. 9km/s, highest 13km/h). There are no faults detected by ABS system. Is this a feature, that the ABS is not able to show more than 48km/h or should it show also higher speed?

I am also concerned about the Speed Encoder Errors (G44-G47) values - there is min, max, average value, but everything reads 65535. What does this value mean?
 
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Uwe

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Quite a few ABS modules quite handling diagnostic requests once the road speed exceeds some value.

That variance you are seeing: Is that while driving straight ahead? If so, I think it warrants further investigation.

-Uwe-
 
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covex

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You are right - ABS diagnostic light shut off at around 20km/h. The reading from sensors continue OK. The variance could be due to turning - I am not very concerned about it.

picture shows the maximum reading around 43-46km/h but the car continues to accelerate up to 90km/h. When the speed drops bellow 43-46km/h then the readings are correct again.
 
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covex

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Is is possible somehow see together speed values read by crankshaft sensor (MVB in 01 engine) and one from ABS speed sensor (MVB in 03 ABS) using VCDS?
 
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Uwe

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Is is possible somehow see together speed values read by crankshaft sensor (MVB in 01 engine) and one from ABS speed sensor (MVB in 03 ABS) using VCDS?
No, you can't get data from more than one control module at a time.

-Uwe-
 
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