Code P1603?

2018 SUBARU IMPREZA
190,000 MILES • 2.0L • 4 CYL • 4WD • AUTOMATIC
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LEO2012P
  • MEMBER
  • 2 POSTS
Car almost stalled dropped low rpm while in park.
All lights came on and code is p1603, car runs fine, with a rpm drop and hesitation one time at 70 MPH. Going to start multimeter testing sensors now but don’t know where to start.
May 21, 2023 at 12:10 PM
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BORIS K
  • CAR REPAIR CONTRIBUTOR
  • 836 POSTS
Hello,

For your model Subaru Impreza there is a possible software update for the engine control module

I would suggest contacting your nearest Subaru dealer to confirm this.

A link for the field action:
https://subaru.oemdtc.com/1570/ecm-reprogramming-for-dtc-p1603-engine-idle-drop-or-stall-2017-2019-subaru-impreza-2018-2019-crosstrek

Cheers, Boris
May 22, 2023 at 1:17 AM
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