BMW 745e G11

The KLE (Komfort-Lade-Elektronik) is the onboard charger that converts mains AC power into DC to charge the high-voltage battery. It is widely reported as the most common failure on BMW PHEVs, including the 745e. Symptoms include 'Unable to charge' errors, a flashing red ring on the charging port, and 'Mains power too low' warnings despite a normal mains supply. The module typically fails between 3 and 6 years of age regardless of mileage. BMW dealerships charge approximately €2,000-2,500 for replacement including coding and labour. Independent specialists can source the unit and complete the work for €1,500-1,800. Without a functioning KLE the car cannot charge via plug and loses all electric driving capability, though it continues to operate as a conventional petrol vehicle. BMW has occasionally offered goodwill contributions for cars just outside warranty but most used-car buyers will bear the full cost. Specialist repair of the KLE circuit board (rather than full replacement) is emerging as a lower-cost option at around €800-1,200 through specialist firms.

Air suspension is standard on the G11 7 Series. The rubber bladders degrade from temperature cycling and UV exposure, typically developing leaks between 80,000 and 130,000 km. Rear springs tend to fail first. Symptoms include one corner sitting lower after overnight parking, the compressor running constantly, or dashboard suspension warnings. An OEM air spring from BMW costs approximately €800-1,200 per corner installed at a dealer. Aftermarket alternatives from Arnott or Bilstein reduce the cost to around €500-700 per strut. If the compressor has been overworked due to a slow leak, it may also need replacement at €500-800. A full suspension refresh covering four struts and a compressor can reach €3,500-4,000 at a dealer. Independent specialists with rebuilt OEM struts can bring this down to around €2,000-2,500 for a full set.

The 12 kWh lithium-ion battery pack sits beneath the rear seats. Over time, individual cells can degrade or develop imbalances, reducing the usable electric range. BMW guarantees at least 70% capacity over the warranty period (8 years / 160,000 km in most EU markets). Once outside warranty, a full battery replacement costs approximately €8,000-10,000. Individual cell module replacements are sometimes possible at BMW or through specialist hybrid workshops for €3,000-5,000, depending on how many modules are affected. Early 745e models from 2019 are approaching the end of their 8-year warranty window from 2027 onward. A BMW dealer can read battery health data via ISTA diagnostics. Reduced range is the most common symptom; complete failure is rare. The 2020 PHEV battery recall (Samsung manufacturing debris causing short-circuit risk) affected some 2021 745Le models. Verify recall completion before purchase.

The B58 engine uses an integrated electric water pump and thermostat housing with plastic components that become brittle from heat cycling. Failure typically occurs between 80,000 and 120,000 km. Symptoms include coolant warning lights, reduced cabin heating, and in severe cases engine overheating. The integrated assembly costs approximately €400-600 for the part, with labour adding another €400-600 due to accessibility in the engine bay. BMW dealers typically charge €1,400-1,800 for the complete job. Independent specialists can complete it for €800-1,200. It is standard practice to replace the water pump and thermostat together since both share the same housing. An electronic coolant bleeding procedure is required after replacement to prevent air pockets.

The 745e uses a high-voltage electric AC compressor rather than an engine-driven unit. This compressor handles both cabin air conditioning and battery pack thermal management via a shared refrigerant loop. If it fails, the battery cooling system is compromised and the car may restrict electric driving to protect the cells. OEM replacement at a BMW dealer runs approximately €2,500-3,000 including HV-rated labour and refrigerant recharge. Independent specialists with HV certification can source aftermarket units and complete the work for €1,500-2,000. The failure is not as commonly reported as the KLE issue, but becomes more likely on cars beyond 100,000 km. Symptoms include poor cabin cooling combined with reduced electric range or battery temperature warnings.

The oil filter housing gasket and the adjacent plastic coolant vent hose are known weak points on B58 engines. Both degrade from engine heat, typically showing symptoms between 60,000 and 100,000 km. The primary source of leaks near the oil filter housing is often the brittle plastic coolant vent hose rather than the gasket itself. Symptoms include visible oil residue on the engine block or a slight burning oil smell. Independent mechanics charge approximately €400-600 for gasket replacement including the coolant hose. BMW dealers typically quote €700-900. The repair itself is straightforward if caught early, but ignoring a leak can lead to oil dripping onto hot exhaust components.

The 745e has no traditional alternator. Instead, a DC-DC converter steps down voltage from the high-voltage battery to maintain the 12V system. If the SME (Safety Management Electronics) detects a fault and opens the HV contactors, the DC-DC converter can no longer charge the 12V batteries. This means simply driving the car will drain the 12V system because nothing is replenishing it. Symptoms include a dead 12V battery after short trips, multiple warning messages on startup, or a complete no-start condition. A 12V battery replacement costs €200-300 (AGM type required). If the DC-DC converter itself fails, replacement runs €800-1,200 at an independent specialist. Cars that sit for extended periods without being plugged in are particularly vulnerable since the HV battery slowly depletes, eventually leaving insufficient voltage for the DC-DC converter to maintain the 12V system. A quality trickle charger is recommended for cars not driven weekly.