Dive Brief:
- BMW Group has recalled 720,796 vehicles for a possible short in the engine water pump electrical connector, which can increase the risk of a fire, according to the National Highway Traffic Safety Administration.
- The recalled models include certain X1, X3 and X5 SUVs, the Z4 Roadster, 228i, 228xi, 328i, 328xi Gran Turismo, 428i, 428xi and 525i from model years 2012 through 2018.
- BMW was first made aware of the water pump electrical connector problem in March, after the company was contacted by the Korean Ministry of Land, Infrastructure and Transport regarding an incident on a BMW vehicle that included a “thermal event.”
Dive Insight:
After being notified of the incident in South Korea, BMW began collecting and analyzing electric water pumps and the electrical connectors from global field vehicles in April. It included collecting parts from vehicles that experienced a thermal event and others that did not.
The automaker was also made aware of another thermal event on a vehicle in January in the U.S.
After BMW’s investigation was initiated, its engineers found that the sealing of the water pump’s electric plug connector could be shorted by fluid dripping from the engine intake air hose in rare cases.
In July, BMW was made aware of a second field U.S. incident and discussions were held with the suppliers of the water pump and the plug connector to analyze possible root causes.
Following this investigation, BMW engineers confirmed their hypothesis of fluid dripping from the intake air hose as the root cause of the electrical short. Although the recall includes 12 different models, the estimated percentage with the defect is 1%, according to the NHTSA.
On Aug. 6, BMW decided to conduct a voluntary safety recall of the vehicles out of an abundance of caution.
Unlike many other vehicles that use belt-driven water pumps, the ones used by BMW are electronically controlled, allowing for more precise temperature control of the engine to improve performance. The impellers of these water pumps are driven by an electric motor rather than a belt.
To address the issue, BMW dealers will inspect and replace the water pump and plug connector on the recalled vehicles, as necessary. Dealers will also install a protective shield for the electrical connector to prevent fluid intrusion, free of charge.
As of Aug. 1, BMW is aware of approximately 18 customer complaints in the U.S. that may be related to the issue, but has not received any reports of accidents or injuries.
Owner notification letters are expected to be mailed Oct. 4.
