Powertrain, generic (extended)

P2D89 Fan 1 Control Module Supply Voltage Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2D89 concerns the power feed of the fan 1 control module: the voltage at its supply terminal, or the value the module reports back, is missing or outside the permitted window. Porsche uses the code in the DME of the 2021–2023 718 Cayman GTS 4.0, Boxster GTS 4.0, Cayman GT4 and Spyder and names it radiator fan 1 (left), power supply. Technical Information 198/22 explains that a software fault could set P2D89 together with P2D8C under certain start-up conditions; drivers noticed weak air conditioning and sometimes an engine control warning, and reprogramming the DME cures it. Where no such software issue applies, check the fan fuse, the heavy supply cable, its ground and the plug for corrosion or heat damage, ideally measuring voltage drop under load. Fan 2 has P2D8C.

Likely causes

Blown fuse, loose terminal or high-resistance supply cable to the fan module
Engine control software that misjudges the fan supply during start-up (Porsche 198/22)
Corroded or loose ground of the fan module
Weak battery or charging system dropping the supply during high fan load

Symptoms

  • Radiator fan intermittently without function
  • Reduced air-conditioning performance
  • Engine control warning in the instrument cluster

Repair estimate

DifficultyMediumDIY possible
Parts and labour€0–400
Time0.5–2 h

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

Parts involved

fan control module 1wiring harnessecm

Related codes

P2D87P2D88P2D8CP0485P0480

References: static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu.