Wheel speed sensor questions

Discuss which Sensors work best with these ECUs and share how you are using inputs and outputs
matthud322
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ECU Model: S60 Pro
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Location: New York, USA

Wheel speed sensor questions

Post by matthud322 »

I want to add a wheel speed sensor to my setup on my S60. I don't need it for traction control, I just want it to be able to use it for a speedometer and MPG logging. The manual talks about adding a shaft speed sensor to determine what gear you are in, and that appears to be a different input. Which one should I use for the speedometer input? Will it still read from the sensor if traction control is turned off? Can a hall effect sensor with a 12v output be used on the wheel speed inputs without causing any problems?
Joey
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Joined: Tue Sep 06, 2011 10:28 pm

Re: Wheel speed sensor questions

Post by Joey »

I have been wondering if there is a way to change ignition timing per gear. I see the firmware update for gear postion off shaft speed sensor also, any info on wiring for shaft speed would be great.
landychris
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Re: Wheel speed sensor questions

Post by landychris »

It used to be just connection one up to the undriven wheel sensor input (left?) for speed and mpg, not used the gear sensor connection as it takes away flat shifting iirc
stevieturbo
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Re: Wheel speed sensor questions

Post by stevieturbo »

the shaft speed sensor is purely for gear calculation

The road speed input needs to be the normal undriven wheel speed input.
matthud322
Posts: 14
Joined: Wed Aug 03, 2011 1:38 pm
ECU Model: S60 Pro
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Location: New York, USA

Re: Wheel speed sensor questions

Post by matthud322 »

stevieturbo wrote:The road speed input needs to be the normal undriven wheel speed input.
Do you know if I can use a hall effect with a 12v output signal on that input without issues?
stevieturbo
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Re: Wheel speed sensor questions

Post by stevieturbo »

Dont know. I just use a regular GT101 which is 5v powered and output.

Are you sure the sensor gives a 12v output ? That would be less common.
Jon K
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Re: Wheel speed sensor questions

Post by Jon K »

Hall sensor doesn't actually give out any power. Some hall sensors can handle 4.5 - 24vdc. You need to look at the spec for your given sensor. The output is a "sinking" output that closes. The DTA actually supplies the "voltage" for the incoming signal because there is a 1K ohm pull-up resistor to 5v internally on the ECU.
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stevieturbo
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Re: Wheel speed sensor questions

Post by stevieturbo »

Jon K wrote:Hall sensor doesn't actually give out any power. Some hall sensors can handle 4.5 - 24vdc. You need to look at the spec for your given sensor. The output is a "sinking" output that closes. The DTA actually supplies the "voltage" for the incoming signal because there is a 1K ohm pull-up resistor to 5v internally on the ECU.
So does the sensor actually ground the "signal" line upon a pulse ?
matthud322
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ECU Model: S60 Pro
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Location: New York, USA

Re: Wheel speed sensor questions

Post by matthud322 »

The sensor I have, actually has a built in pull up to the sensor's power. I have it powered by 12v so it will drive the speedo on the dash.
Jon K
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Re: Wheel speed sensor questions

Post by Jon K »

stevieturbo wrote:
Jon K wrote:Hall sensor doesn't actually give out any power. Some hall sensors can handle 4.5 - 24vdc. You need to look at the spec for your given sensor. The output is a "sinking" output that closes. The DTA actually supplies the "voltage" for the incoming signal because there is a 1K ohm pull-up resistor to 5v internally on the ECU.
So does the sensor actually ground the "signal" line upon a pulse ?
Yep - on a sinking sensor the output is open, so the CPU inside the DTA sees the high signal (5v with 1K ohm pull up). When a pulse comes out (tooth present) of the sensor, it pulls that 5v down to 0v and the 1K ohm resistor limits current to the "short" to ground.

Matthud - be careful, the DTA won't like that. It has an internal pull up. I imagine if you put 12v into the DTA wheel speed input you'd be back-feeding the 5V power supply circuit with 12V
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