Powertrain, generic (extended)

P2CC3 Generator Voltage Sense Circuit B Low

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2CC3 is stored when generator sense circuit B reports a voltage below its lower limit, in practice often close to zero. Typical causes are an open sense lead, a blown fuse in it or a short to ground; on Chrysler alternators, according to Remy, an internal 2.4 kΩ resistor shields the sense terminal against such a ground fault. The risk lies in the regulation: if the controller believed a too-low reading, it would raise field current and overcharge the battery, which is why a controller that has recognised the fault can fall back to a substitute value or a fixed set point instead. No manufacturer documents P2CC3 publicly. CARB demands MIL monitoring of charging inputs only where emissions or other diagnostics depend on them. High signal: P2CC4; circuit A low: P063C.

Likely causes

Sense wire B broken or its fuse blown
Sense wire B chafed and shorted to ground
Corroded sense terminal at the alternator or module

Symptoms

  • Charging warning lamp on
  • Charging voltage too high or held at a fixed value
  • Overcharged battery, bright lights

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–600
Time0.5–2 h

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

Parts involved

generator voltage sense circuitalternatorwiring harness

Related codes

P2CC1P2CC2P2CC4P063CP0562P0563

References: autoprollc.com, serdia.deutz.com, law.cornell.edu.