Skip to content
Book on WhatsApp

P063C

Generator Voltage Sense Circuit A Low

Same as P063A with the sense voltage below the plausible range.

  • Check engine light: Yes
  • Emissions related: No
  • Repair difficulty: medium

Symptoms

  • Check engine light on
  • Possible limp mode or no-start
  • Multiple follow-up faults across modules
  • Reset/relearn may be needed after repair

Common causes

Ordered by how often each turns out to be the cause.

  • Sense line shorted to groundCommon
  • Pack cell imbalance approaching service thresholdLess likely
  • Ground point with elevated resistanceLess likely

Parts involved

  • Alternator Voltage Sense A

P063C is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.