# Service bulletin 2028794/9

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 11025077
- Published by NHTSA: 2025\-11\-06
- Manufacturer's number: 2028794/9
- Manufacturer's date: 2025\-10\-24
- NHTSA component: ENGINE

## NHTSA's summary

Engine coolant mixture \- Restrictions on use of desalinated water. Technical Background: An important factor of influencing the cooling system efficiency is the water used in the mixture Due to the different ingredients and characteristics existing in each country or even region, Bentley has decided to define the quality of water for cooling systems

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11025077-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11025077-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Engine

## Vehicles listed

- 2017 to 2023 BENTLEY BENTAYGA
- 2025 to 2026 BENTLEY BENTAYGA
- 2019 to 2026 BENTLEY BENTAYGA HYBRID
- 2004 to 2026 BENTLEY CONTINENTAL GT
- 2007 to 2026 BENTLEY CONTINENTAL GT CABRIO
- 2006 to 2013 BENTLEY FLYING SPUR
- 2014 to 2026 BENTLEY FLYING SPUR
- 2022 to 2024 BENTLEY FLYING SPUR HYBRID
- 2009 to 2010 BENTLEY MULSANNE
- 2011 to 2019 BENTLEY MULSANNE
- 2024 BENTLEY redundant BENTAYGA

## Other bulletins for the same vehicles and component

- [2083110/1](/bulletins/11038253.md), 2026-10-07, Service bulletin: ENGINE; ELECTRICAL SYSTEM. Engine Management Light \- N91 Coolant Valve \| Flying Spur Hybrid Technical background: Some 22MY Flying Spur Hybrid vehicles may exhibit an illuminated Malfunction Indicator Lamp \(MIL\) due to DTC P26B100 \- Engine Coolant Bypass Valve "A" Stuck Closed being stored in the Thermal Management Control Module \(00C5\). When this DTC is present, the Thermal Management system displays MIL light on the DIP, resulting in DTC P162400 being stored in the Engine Control Module. A software update is available to address this condition.
- [2083066/1](/bulletins/11037173.md), 2026-09-09, Service bulletin: ELECTRICAL SYSTEM; ENGINE. Drive system fault \- Camshaft position sensor DTC. Customer may state following concerns: Drive system fault on the dashboard Abnormal engine noise on engine start\-up
- [2061369/14](/bulletins/11037161.md), 2026-09-09, Service bulletin: ELECTRICAL SYSTEM; ENGINE. Engine Overheating \- Warning in the DIP \| V8 Kovomo. Customer statement / workshop findings: One or a combination of the following symptoms are evident • Engine overheat warning in the DIP \(Engine overheating\) • Unusual cooling fan operation at high temperatures • P19F700: Low engine coolant temperature indicator lamp coolant too warm • Signs of coolant in the vacuum hoses for switch valve N649
- [2082212/2](/bulletins/11037098.md), 2026-09-05, Service campaign: ENGINE; ELECTRICAL SYSTEM. Subframe Mount Control Unit \- Calibration Update \| Bentayga Series \| 26\-27MY \(SC26/16\) Technical background: On the affected vehicles the current dataset in the J931 power unit mounting control unit causes unintended active operation of the engine mount. The updated calibration replaces the existing dataset with a revised version, deactivating the active mount function.
- [2061369/13](/bulletins/11037097.md), 2026-09-05, Service bulletin: ELECTRICAL SYSTEM; ENGINE. Engine Overheating \- Warning in the DIP \| V8 Kovomo. Customer statement / workshop findings: One or a combination of the following symptoms are evident: • Engine overheat warning in the DIP \(Engine overheating\) • Unusual cooling fan operation at high temperatures • P19F700: Low engine coolant temperature indicator lamp coolant too warm • Signs of coolant in the vacuum hoses for switch valve N649
- [2081085/2](/bulletins/11035939.md), 2026-08-06, Service bulletin: ELECTRICAL SYSTEM; ENGINE. V8 Engine \- Ticking Noise, Misfiring and Possible Low Oil Pressure Indications. Customer statement: The customer may report an audible ticking noise from the top of the engine, low oil pressure warnings / MIL on the Driver Information Panel, and/or misfiring during engine operation
- [2051187/13](/bulletins/11035901.md), 2026-08-05, Service bulletin: ELECTRICAL SYSTEM; ENGINE. Poor Engine Running Complaints \(Misfires\) Petrol Engines Only. Customer statement / workshop findings: • Poor engine running • Reduced power • Engine warning lamp illuminated • Symptom related DTC’s evident within the applicable engine control unit\(s\)
- [2068273/6](/bulletins/11035569.md), 2026-08-03, Service bulletin: ELECTRICAL SYSTEM; ENGINE. Multiple random misfires evident during PDI.
- [2065664/6](/bulletins/11035418.md), 2026-08-01, Service bulletin: ENGINE; ELECTRICAL SYSTEM. Bentayga V8 Kovomo \- Engine MIL light on \- DTC “O2 Sensor Signals Swapped Bank 1 Sensor 2/ Bank 2 Sensor 2. Customer statement / workshop findings: DTC P004100: “O2 Sensor Signals Swapped Bank 1 Sensor 2/ Bank 2 Sensor 2 is evident within address 0001 \(Engine control unit\) and MIL light active after attempting to conduct a readiness test
- [2081236/2](/bulletins/11035417.md), 2026-08-01, Service bulletin: ENGINE; VISIBILITY/WIPER; ELECTRICAL SYSTEM. Loss of Cabin Heat During Engine Operation \| Bentayga \- V8. Customer Statement: Customers may report that the air conditioning system blows only cold air when the engine is running. Warm air is only available after switching off the engine. The concern is commonly reported after engine removal or recent repair work.

JSON: [/v1/bulletins/11025077](/v1/bulletins/11025077)

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