Stumbled across this trying to resolve a fault on my r34 gtr. I wondered where that impedance was coming from. The diagram shows atessa pin 34 as sensor ground connected to pin 43 of ecm, except ecm pin out for pin 43 is ign switch start signal according to manual. However, something is giving me an unstable throttle position signal when driving causing the car to surge, when tps signal pin 23 is taken away from the atessa the car drives normal again. The Mfd still shows the thottle % fluttering +/- ~5% with steady throttle and at idle up to 2% flutter when the atessa has the tps signal removed. At this stage it’s seeming like an ecm or atessa computer fault. Anything else anyone could think of that might cause this?
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