Hey Guys,
The ABS light in my E0 is coming on once I start moving. This tells me I have a bad wheel sensor. I tried the trick where I would unplug all but one sensor to identify the problem, but that did not work. The light would always turn on unless I left all 4 sensors unplugged. Instead of spending ~$500 dollars replacing all the sensors I wanted to track down the problem.
With the help of a friend at an awesome shop, we scoped the wheel sensors and saw this:
Just as an FYI wire colors correspond with graph colors (The only exception being BLUE = WHITE.
According to the ETM that means:
White = RH rear wheel sensor
Red = LH front wheel sensor
Green = LH rear wheel sensor
Yellow = RH front wheel sensor
Note: All these captures are taken with the sensors plugged into the computer.
Low Speed.
Higher Speed.
After looking over these captures, we determined that the green signal (LH REAR) was much weaker and potentially causing the problem. I swapped out the sensor with a known good used one. I also swapped the half shaft incase the ring was the problem.
This did not cure the problem so it was back to the shop to have it scoped again.
Lower Speed.
Higher Speed.
This time we noticed that the red and green signal was acting almost like a wave. I am stumped at this point and I would really like to get ABS working.
Here is what I have done:
Replaced front wheel bearings (New ABS Rings)
Checked the wiring to each sensor with an ohm meter (Everything checks out)
Swapped rear sensors side to side.
Tried a different ABS computer.
I also have scopes with the computer unplugged. (Sensor grounded with the scope) I can get more detailed screen shots or other info if you need it.
Thanks for the assistance!
The ABS light in my E0 is coming on once I start moving. This tells me I have a bad wheel sensor. I tried the trick where I would unplug all but one sensor to identify the problem, but that did not work. The light would always turn on unless I left all 4 sensors unplugged. Instead of spending ~$500 dollars replacing all the sensors I wanted to track down the problem.
With the help of a friend at an awesome shop, we scoped the wheel sensors and saw this:
Just as an FYI wire colors correspond with graph colors (The only exception being BLUE = WHITE.
According to the ETM that means:
White = RH rear wheel sensor
Red = LH front wheel sensor
Green = LH rear wheel sensor
Yellow = RH front wheel sensor
Note: All these captures are taken with the sensors plugged into the computer.
Low Speed.
Higher Speed.
After looking over these captures, we determined that the green signal (LH REAR) was much weaker and potentially causing the problem. I swapped out the sensor with a known good used one. I also swapped the half shaft incase the ring was the problem.
This did not cure the problem so it was back to the shop to have it scoped again.
Lower Speed.
Higher Speed.
This time we noticed that the red and green signal was acting almost like a wave. I am stumped at this point and I would really like to get ABS working.
Here is what I have done:
Replaced front wheel bearings (New ABS Rings)
Checked the wiring to each sensor with an ohm meter (Everything checks out)
Swapped rear sensors side to side.
Tried a different ABS computer.
I also have scopes with the computer unplugged. (Sensor grounded with the scope) I can get more detailed screen shots or other info if you need it.
Thanks for the assistance!
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