Question

1997 GMC Sierra 1500 with engine code P1406, the truck will not start without a jump new battery new cables it just cranks faster

Answer 1

P1406 EGR valve pintle position circuit

This code affects the performance of the MAP sensor. Disconnect the EGR connection and restart the vehicle if the perfomance return and its easier to start replace the EGR

Answer 2

P1406 GMC Code - EGR Valve Pintle Position Circuit
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