ECMTuning - wiki

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<h1>TPS Adjustment Procedure</h1> <div class="level1"> <p> The ECU wants to see 0.63v from the TPS sensor when your foot is off the throttle and greater than, say, 4.6v when you're fully on it. You can datalog TPSvolts to see what the ECU is really getting. The value at idle (foot off the throttle) is probably more important than the value at wide open throttle. A value that's too high at idle can prevent the idle switch from activating or it will prevent the "simulate idle switch" functionality from working properly. </p> </div> <h1>Details</h1> <div class="level1"> <p> To adjust what the ECU sees, you can use the TPS Adjustment dialog. Start by disabling TPS adjustments. Then datalog RawThrotPos. That value is the real value datalogged from the ECU when you display TPSVolts or ThrotPos. Move the throttle from fully closed to fully open. Note the RawThrotPos at each point (fully closed and fully open) as follows. </p> <pre class="code">Vc = RawThrotPos when throttle closed Vo = RawThrotPos when throttle open </pre><p> </p> <p> Next, solve for scale and offset as follows, using the values collected in the previous step. </p> <pre class="code">Scale = 223 / (Vo - Vc) Offset = 32 / Scale - Vc </pre><p> </p> <p> Note that Scale will be a number like 1.05 indicating 105% in the DSMLink TPS dialog. </p> <p> Lastly, enable TPS adjustments and enter the offset and scale values. </p> </div>