P2D89Fan 1 Control Module Supply Voltage Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- 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.
- What you may notice
- Radiator fan intermittently without function
- Reduced air-conditioning performance
- Engine control warning in the instrument cluster
- Likely causes
- LikelyBlown fuse, loose terminal or high-resistance supply cable to the fan module
- PossibleEngine control software that misjudges the fan supply during start-up (Porsche 198/22)
- PossibleCorroded or loose ground of the fan module
- RareWeak battery or charging system dropping the supply during high fan load
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €0 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.