Powertrain, generic (extended)

P2D59 Generator B Over Temperature

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modePossible

P2D59 indicates that generator B has become too hot. Which machine B means is up to the manufacturer: a second alternator in a dual charging system or a second motor-generator in a hybrid. No manufacturer documents P2D59 publicly. For generator A, Mitsubishi describes the hybrid case under P0A3B on the 2023 Outlander PHEV: a W-phase coil temperature of 199 °C or more for one second sets the code. On the alternator side, Infineon's LIN regulator TLE8881-3 raises a high-temperature flag as soon as the chip passes a programmable compensation threshold, where it also starts lowering the voltage set point. Typical causes are blocked cooling air or oil flow, sustained overload, a failed fan or a misreading sensor. Output is cut back, so charging or hybrid power may be limited.

Likely causes

Obstructed cooling air path or reduced oil/coolant flow to the generator
Sustained high electrical load at low engine speed
Temperature sensor or regulator measuring wrongly

Symptoms

  • Reduced charging output or charge warning
  • On hybrids, limited electric or series-mode power

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–3,000
Time1–6 h

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

Parts involved

generator bvoltage regulator

Related codes

P2D57P2D58P0A3BP0A3E

References: mitsubishitechinfo.com, infineon.com, law.cornell.edu.