Cooling System - Coolant Fan ON With Ignition OFF Via Moisture
No-load (quiescent) current too high, engine suction fan starts up without obvious cause after ignition "off", battery discharged
Topic number LI20.40-P-053718
Version 1
Design group 20.40 Fan, fan clutch
Date05-07-2012
Validity Models 203, 164, 251, 204, 207, 212, 219, 216, 221, 218 with Brose/ Temic radiator fan
Reason for change Other vehicle model designations included
Complaint:
- Radiator suction fan starts up without obvious cause although the ignition has been off for longer than 30 minutes
- Radiator suction fan changes to limp-home mode (runs at 100% output) while driving, with display message (cooling system) in instrument cluster
- Battery discharged
Cause:
The electric radiator suction fan may start up by itself with ignition "off" due to moisture ingress.
Mercedes-Benz A220 2020 Page 428
In menu "Behavior of quiescent current" (Functions Views / Overall Vehicle / Power Supply / Actual Values / Battery Sensor) read out the 5 stored
data records. If at least one of the data records contains a no-load current entry of >10A and if the mileage reading in SDS menu agrees with the
actual mileage stand at which the vehicle battery was discharged, the radiator fan may have been the cause of the fault.
Only Brose/Temic fans with the following part numbers are affected:
A221 500 11 93, A221 500 09 93, A221 500 10 93, A164 500 04 93, A164 500 05 93, A203 500 16 93, A203 500 14 94, A204 500 02 93, A204
500 04 93. Refer to the parts table for part number replacement (valid at the time of publication).
Remedy:
Replace radiator fan as per EPC.
