I'm trying to track down a P0641 5v reference error on an LS3 E-Rod motor. The motor and tune are stock. When the code appears, the ECM completely disables the throttle input. It only allows idle.
At one point it gave me a P2122 so I replaced the throttle pedal assembly with no change.
I logged a session (attached) and can see that the MAP pressure drops significantly a moment before the ECM goes into limp mode. On the log, (sorry about the repeat parameters) at 4:23 the MAP drops from 39 (kPa) to 13. A second later the motor goes into limp mode. Same at 10:02. Map goes from 31 to 3.
My hope is it's just a MAP sensor. I don't see any wiring issues.
I'm not sure if I'm on the right track here. It seems like HP Tuners should be able to pinpoint the problem if I know what to look for.
Thanks for any advice you might have to offer.
-Dave
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