Powertrain, generic (extended)

P2DCA Starter/Generator Excitation Current Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2DCA is set when the field current of a starter/generator with electrically excited rotor does not stay steady but drops out or jumps for short moments, without staying beyond the low or high limit long enough for P2DC8 or P2DC9. The rotor coil of a claw-pole machine such as Valeo's 48 V iBSG receives its current through brushes running on slip rings, so worn or sticking brushes and dirty or worn rings are typical sources of such dropouts; a loose plug on the field leads or a cracked solder joint in the excitation bridge can do the same. Each dropout briefly collapses the rotor field, making torque and charging current fluctuate. No manufacturer documents P2DCA publicly. Drivers may notice uneven engine restarts or a flickering charge warning. General fault: P2DC7.

Likely causes

Worn or sticking brushes, dirty or worn slip rings
Loose connector or terminal on the field leads
Cracked solder joint in the excitation bridge of the controller

Symptoms

  • Charge warning that comes and goes
  • Jerky or delayed restarts after start-stop
  • Electric boost and recuperation work only at times

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–2,000
Time1–4 h

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

Parts involved

starter generator excitation circuitstarter generatorwiring harness

Related codes

P2DC7P2DC8P2DC9P065B

References: valeo.com, ti.com, law.cornell.edu.