Powertrain, generic (extended)

P257F Engine Hood Switch Circuit High

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modeNo

P257F is the high-side counterpart of P257E: the hood switch reading rises above the top limit, which points to an open signal line, a pin that has backed out of its connector, or a short to a voltage source. In GM's 2018 engine table 18OBDG04 the limit for a resistance-coded switch is 3,620 ohms or more, and the 2019 hybrid table 19OBDG01 uses 71.5 % of range; both need 80 failures within 100 samples and are Type B with two trips. A Stellantis STAR case for 2021–2023 Wrangler models sends technicians to connector XY103A at the left front of the engine compartment, where loose terminals can set P257F together with P152E or P0073. GM's PIE0834 also names it on its electric trucks with latch faults. The driver sees a check engine lamp, possibly a hood warning, and no automatic engine stop.

Likely causes

Open hood switch signal wire or unplugged switch
Loose or pushed-back pins in a front harness connector
Signal line shorted to a voltage source

Symptoms

  • Check engine lamp on
  • Engine stop-start stays inactive
  • Hood warning may be shown or may be missing when the hood is really open

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–250
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hood switch

Related codes

P257DP257EP254F

References: gsi.ext.gm.com, static.nhtsa.gov, gsi.ext.gm.com.