how to eliminate the voltage offset?

s300 and SManager software questions & answers
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Luke
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how to eliminate the voltage offset?

Post by Luke »

is there a possibility to eliminate the voltage offset for the wideband?

using the Innovate LM2, connected through the "tuner harness" to the wideband input with the same ground as the ECU.

i think, that the difference between the "real" voltage and this difference is depending on the ground, which the LM2 is getting through the cigarette lighter.

will test with a current pickup directly at the battery, hoping, that there will be a difference, but maybe you guys have some solution.

another solution would be using the digital input of the V2 for it and getting the data via the MTS port of that LM2, but that won't be possible for tuning.

best regards Lukas

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Hondata
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Re: how to eliminate the voltage offset?

Post by Hondata »

The wideband may have two grounds - power and signal. The signal ground must go to the same ground as the ECU (thermostat housing).
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Luke
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Re: how to eliminate the voltage offset?

Post by Luke »

signal has the same ground as the ECU.

the question is, that i want to eliminate the offset completly. so hopefully with the same ground? that would solve the problem.

best regards Lukas

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Hondata
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Re: how to eliminate the voltage offset?

Post by Hondata »

What is grounded through the cigarette lighter outlet then?

If the ECU & wide-band grounds are in the same place then the only other factor is the voltage drop down the ground lines from the power draw from each device floating the ground above battery negative. For the wide-band this is usually from the o2 sensor heater current draw, which is why a wide-band with a separate power ground is better.
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Luke
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Re: how to eliminate the voltage offset?

Post by Luke »

the signal ground is the same as the ECU ground.

the power ground is through the cigarette lighter. i think here is the "problem"

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Spunkster
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Re: how to eliminate the voltage offset?

Post by Spunkster »

It is best to not use thecigarette lighter for powering things, wspecially devices that go to the ECU. USe the empty switched 12v slots in the fuse box under the dash, and use a good solid chassis ground.

Luke
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Re: how to eliminate the voltage offset?

Post by Luke »

that would work nice in my car, for sure.

but when "in the field" this isn't the best solution.

will check it out directly with the battery. maybe this will be a "fast" solution.

best regards Lukas

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