What the source says
The documented condition
BMW SIB 17 03 20 applies to specified G01 X3 vehicles built through March 31, 2019 when a coolant leak is confirmed at or below 5°F (minus 15°C). The bulletin attributes the condition to quick-connect O-rings that may not seal in extreme cold. It is not a general explanation for coolant loss in warmer weather.
Compare the pattern
Symptoms and vehicle scope
Words owners may use
- BMW leaks coolant only when freezing
- coolant puddle after cold night
- top up coolant warning in winter
- X3 coolant hose leaking in cold
- low temperature coolant warning
- coolant disappears below zero
Symptoms in the record
- Low high-temperature or low-temperature coolant reservoir
- Coolant visible under the vehicle during extreme cold
- Check-control message ID166 asking to top up coolant
- Stored dry-running protection or A/C compressor faults listed in the bulletin
Vehicles and limits
- BMW G01 X3 vehicles built through March 31, 2019
- Confirmed coolant leak at or below 5°F (minus 15°C)
- Engine-specific hose attachments in the bulletin must be followed
20A20120A20980120AManufacturer position
What the official procedure directs
BMW directs technicians to pressure-check both cooling circuits and replace the complete set of listed coolant lines for the applicable engine when a qualifying cold-weather leak is confirmed.
Mileage context
The bulletin uses build date, outside temperature and confirmation of a leak rather than mileage.
Original evidence
Open the documents behind this record.
Manufacturer bulletin · SIB 17 03 20 · May 7, 2020
Coolant-line quick disconnects leak at or below 5°F (minus 15°C)
Includes G01 X3 vehicles built through March 31, 2019 and requires the leak to occur in the stated temperature condition.
Repair paths and safe checks
Match the action to the evidence.
Pressure-test both cooling circuits
A BMW technician should confirm the leak under the bulletin conditions, test the high and low temperature circuits, then replace the engine-specific coolant lines listed in the attachment.
Record temperature and cold fluid level
Record the overnight temperature, warning text and location of any puddle. Photograph reservoir levels only after the engine is completely cold.
Never open either cooling circuit while hot or pressurized.
Record reviewed in the source on August 2, 2026. Confirm the current document and VIN instructions before arranging work.