I am not sure a bad EHA would cause an instant shutdown. EHA control is I think the only output from the ECU (fuel injection computer), and the car should run without the ECU control, without such control, the emission outputs cannot be controlled, and proper dynamics cannot be achieved, i.e. acceleration/decceleration control, but the car should run. So in my opinion, EHA failure is less likely to cause your problem.

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Saumil S. Patel