mk4 Fan Control Module (J293) chart and A/C tips

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Ross-Tech Employee
Staff member
Ross-Tech Employee
Jan 29, 2014
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DO NOT ASK QUESTIONS HERE! If you need help with your car, start a new forum post in the appropriate section.
On the VW mk4 platform, the Fan Control Module (J293) is dumb, you can't scan it VDCS or the factory scan tool. If the A/C doesn't work, it will require old fashion detective work.

J293 pin out chart:

MK4 A/C quick and dirty checking:
A/C compressor clutch?Radiator Fans?Sensor
NopeNopeAmbient Temp Sensor (F38) @ T14/5 and T14/14
NopeNopeSignal from the Instrument Cluster @ T14/13
NopeNopeHigh Side Pressure Sensor (G65) @ T14/2
NopeYesIssue with A/C clutch circuit (N25)
NopeYesECM/TCM signal @ T14/3

  • Terminals can rot inside the terminal housing of the J293. Using a hook tool, gently tug on each of the wires to verify they have not come apart.
  • If the Ambient Temp Sensor (F38) is bad, unplugging it and shorting the terminals together will fix the A/C system after 2 minutes @ idle.
  • While the Fan Control Module (J293) is dumb as dirt, it does monitor amp draw of the A/C Clutch (N25). If the draw is out of factory design (open or short circuit), the Fan Control Module (J293) can cut power to the A/C Clutch (N25).
  • A/C Clutch (N25) should be about 4.5 ohms.
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