How do you check to see if a speed sensor is bad?
08-04-2016, 04:44 PM
#1
Burning Brakes
Thread Starter
How do you check to see if a speed sensor is bad?
Need to check my speed sensors to see if one is bad and causing some codes to pop up. Any suggestions for how to check them and see if they are good or bad?
08-04-2016, 05:39 PM
#3
Are you talking about the wheel sensors for the ABS?
I believe those sensors also provides data for the traction control.
If so, there is a measured value for them if you put a ohm meter across the lead. I had to replace one on my suburban one time and found the info through google and youtube.
This article says it could be a problem in the steering wheel harness as well.
http://www.thevettebarn.com/forums/c...handaling.html
I believe those sensors also provides data for the traction control.
If so, there is a measured value for them if you put a ohm meter across the lead. I had to replace one on my suburban one time and found the info through google and youtube.
This article says it could be a problem in the steering wheel harness as well.
http://www.thevettebarn.com/forums/c...handaling.html
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Corvette505 (08-04-2016)
08-04-2016, 05:48 PM
#5
Safety Car
I've had a similar issue. Here is my thread on it with pics of the repair.
https://www.corvetteforum.com/forums...ode-c0035.html
https://www.corvetteforum.com/forums...ode-c0035.html
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Corvette505 (08-04-2016)
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Corvette505 (08-04-2016)
08-07-2016, 11:13 AM
#7
Le Mans Master
From the articles i have read you could test with ohm meters but it wont show you that you have a problem or what the system believes is a problem.
If it is throwing a wss code it is detecting an out of spec signal on the circuit. If it is not the sensor it is going to be a broke wire between the two.
You would have to disconnect the ebcm wiring harnes, find the correct pins and then do a loop back test to the other end of the harness.
http://www.autoserviceprofessional.c...o-wrong?Page=1
If it is throwing a wss code it is detecting an out of spec signal on the circuit. If it is not the sensor it is going to be a broke wire between the two.
You would have to disconnect the ebcm wiring harnes, find the correct pins and then do a loop back test to the other end of the harness.
http://www.autoserviceprofessional.c...o-wrong?Page=1
08-07-2016, 11:52 AM
#8
If you are getting wheel speed sensor codes they should be directing you to a specific wheel. I have been using a technique learned from working on German cars years ago before they stored ABS codes.
Unplug the sensor and using a DVOM set on AC volts measure the output voltage coming from the 2 sensor terminals while getting a helper to spin the tire fast as you can. Do this on 2 wheels then compare the voltage output. Make sure you spin both tires at the same speed. A good sensor will usually produce about 1v ac and a bad sensor will usually be below .5v ac. You won't find this in a modern service manual because there is simply too much room for interpretation. I find it works great for finding failing sensors that are not yet setting codes and verifying suspect ones. Simply put the bad sensor will produce less or no voltage.
Unplug the sensor and using a DVOM set on AC volts measure the output voltage coming from the 2 sensor terminals while getting a helper to spin the tire fast as you can. Do this on 2 wheels then compare the voltage output. Make sure you spin both tires at the same speed. A good sensor will usually produce about 1v ac and a bad sensor will usually be below .5v ac. You won't find this in a modern service manual because there is simply too much room for interpretation. I find it works great for finding failing sensors that are not yet setting codes and verifying suspect ones. Simply put the bad sensor will produce less or no voltage.
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bo_knows (01-05-2019)
08-07-2016, 12:25 PM
#9
Racer
If you are getting wheel speed sensor codes they should be directing you to a specific wheel. I have been using a technique learned from working on German cars years ago before they stored ABS codes.
Unplug the sensor and using a DVOM set on AC volts measure the output voltage coming from the 2 sensor terminals while getting a helper to spin the tire fast as you can. Do this on 2 wheels then compare the voltage output. Make sure you spin both tires at the same speed. A good sensor will usually produce about 1v ac and a bad sensor will usually be below .5v ac. You won't find this in a modern service manual because there is simply too much room for interpretation. I find it works great for finding failing sensors that are not yet setting codes and verifying suspect ones. Simply put the bad sensor will produce less or no voltage.
Unplug the sensor and using a DVOM set on AC volts measure the output voltage coming from the 2 sensor terminals while getting a helper to spin the tire fast as you can. Do this on 2 wheels then compare the voltage output. Make sure you spin both tires at the same speed. A good sensor will usually produce about 1v ac and a bad sensor will usually be below .5v ac. You won't find this in a modern service manual because there is simply too much room for interpretation. I find it works great for finding failing sensors that are not yet setting codes and verifying suspect ones. Simply put the bad sensor will produce less or no voltage.
08-07-2016, 01:27 PM
#10
Le Mans Master
You can examine the waveforms with an oscilloscope, but there are sensor-specific DTCs. What codes are you getting?
08-07-2016, 03:47 PM
#11
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If you are getting wheel speed sensor codes they should be directing you to a specific wheel. I have been using a technique learned from working on German cars years ago before they stored ABS codes.
Unplug the sensor and using a DVOM set on AC volts measure the output voltage coming from the 2 sensor terminals while getting a helper to spin the tire fast as you can. Do this on 2 wheels then compare the voltage output. Make sure you spin both tires at the same speed. A good sensor will usually produce about 1v ac and a bad sensor will usually be below .5v ac. You won't find this in a modern service manual because there is simply too much room for interpretation. I find it works great for finding failing sensors that are not yet setting codes and verifying suspect ones. Simply put the bad sensor will produce less or no voltage.
Unplug the sensor and using a DVOM set on AC volts measure the output voltage coming from the 2 sensor terminals while getting a helper to spin the tire fast as you can. Do this on 2 wheels then compare the voltage output. Make sure you spin both tires at the same speed. A good sensor will usually produce about 1v ac and a bad sensor will usually be below .5v ac. You won't find this in a modern service manual because there is simply too much room for interpretation. I find it works great for finding failing sensors that are not yet setting codes and verifying suspect ones. Simply put the bad sensor will produce less or no voltage.
08-14-2016, 08:53 PM
#13
Drifting
There is also a speed sensor located at the rear of the car on the top of the rear differential, looking at the car from the rear it' on the top right of the differential and sends a signal to the computer for the speedometer.
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Corvette505 (08-15-2016)