Coolant Circulation Pump
Refer to: WIS 83.40 Automatic Climate Control (ACC) or Heating Ventilation and Air Conditioning (HVAC)
Description - Coolant Circulation Pump
The Coolant Circulation Pump (A31/m1) is also known as - "Auxiliary Water Pump".
Edit required.
Issues - Coolant Circulation Pump
- It may be hard to notice that your coolant circulation pump (A31/m1) is not working properly.
- If the pump is dead, then in cold weather the car could not be heated more than 30C even if ACC was set to "HI".
Parts - Coolant Circulation Pump
- 0 392 020 066" or 0392020066
- A2208350064
Diagnosis - Coolant Circulation Pump
- Error code: B1416 "The component or the signal line to the component A31m1 (coolant circulation pump) has short circuit to positive or overload."
- Note: error code B1416 is thrown if coolant circulation pump draws >5A current.
Testing - Coolant Circulation Pump
- I removed the pump and connected it to 12V DC. The pump did not spin at all (it was completely stuck and I could not rotate it even by hand) and the multimeter showed that it consumed 5.5A current.
Conclusion:
While you can buy a brand new pump for 140 EUR you might as well try to repair it. The reference shows how you can do it.
DIY Procedures - Coolant Circulation Pump
Repair - Coolant Circulation Pump
Acknowledgement of contribution by BenzWorld Member, Pokseva.