Service bulletin B18100C

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
Type	Service bulletin
NHTSA id	10146072
Published by NHTSA	2018-10-29
Manufacturer's number	B18100C
Manufacturer's date	2018-10-16
NHTSA component	ENGINE AND ENGINE COOLING; ENGINE

NHTSA's summary

Servicenews Article - Have a vehicle in your shop with low mileage (less than 1,500 miles) and a hard-to-pinpoint engine knock? We're currently investigating vehicles for hairline fractures in the crankshaft sprocket, and we suspect it may be the cause for this noise.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine

Vehicles listed
ACURA ILX	2017
ACURA TLX	2017, 2018

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
23V751000	2023-11-13. ENGINE AND ENGINE COOLING:ENGINE:HARD PARTS INTERNAL/MECHANICAL
2023603	2023-11-08. Engine

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
B22-009	2025-07-09. Service bulletin. Service Bulletin - Under certain circumstances, after coming to a stop and engaging idle stop the vehicle may not restart automatically due to excessive cylinder pressure and/or low cranking torque. Typically, the client can immediately restart the vehicle by selecting Park and pressing the ENGINE START/STOP button.
B24-022	2025-03-05. Service bulletin. Service Bulletin - The AWD warning light is on with one or more AWD DTCs having been set due to water intrusion into the electric oil pump motor connector area corrodes the terminals.
B16-008	2024-09-10. Service bulletin. Service Bulletin - Drivers may experience a chirping sound coming from the engine area with the engine warmed up due to the high pressure fuel pump is making a chirp.
B23-035	2024-01-17. Service bulletin. Service Bulletin - The MIL comes on during vehicle operation due to variations in the purge control solenoid valve spring, the valve wears unevenly and intermittently sticks. This may result in setting DTC P0441 (Evaporative Emission (EVAP) System Purge Flow Malfunction).
B23-035	2023-12-23. Service bulletin. Service Bulletin - Due to variations in the purge control solenoid valve spring, the valve wears unevenly and intermittently sticks. This may result in setting DTC P0441 (Evaporative Emission (EVAP) System Purge Flow Malfunction).
ONL6AX07052023	2023-07-14. Service bulletin. Owner Notification Letter - Under certain circumstances, after coming to a stop and the idle stop feature engages, the vehicle may not automatically restart. Acura is providing a product update with new PGM-FI software update to fix this issue.
B23-009	2023-04-27. Service bulletin. Service Bulletin - The engine will not crank on the initial startup attempt after the vehicle has been exposed to precipitation and then freezing temperatures. Water can enter the starter motor. In cold temperatures the water can freeze, preventing the starter motor from cranking the engine.
Defect Code 6T6,	2022-07-07. Service bulletin. "Customer letter - Under certain circumstances, after coming to a stop and the idle stop feature engages, the vehicle may not automatically restart. To ensure your confidence in your vehicle. Acura is extending the warranty coverage for starter and starter relays and a valve adjustment related to this condition to 10 years from the original date of purchase with no mileage limitation. This warranty extension provides coverage for the original owner and any subsequent owners. No action is required on your part unless you experience a problem."
Defect Code 6AX,	2022-07-07. Service bulletin. "Customer letter - Under certain circumstances, after coming to a stop and the idle stop feature engages, the vehicle may not automatically restart. Acura is providing a product update with new PGM-FI software update to fix this issue. In addition, to ensure your confidence in your vehicle, Acura is extending the warranty coverage for valve adjustment and starter replacement related to this condition to 10 years from the original date of purchase with no mileage limitation. This warranty extension provides coverage for the original owner and any subsequent owners. No action is required on your part unless you experience a problem."
BTI&05102022901	2022-06-06. Service bulletin. American Honda Motor Co., Inc. (AHM) is searching for certain 2016-2020 MDXs, RLXs & TLXs with a client complaint of the Malfunction Indicator Light (MIL) on with the DTC P030X (Cylinder Misfire Detected), P0171 & P0174 (Rear/Front Bank Fuel System Too Lean), or P219A&B (Air-Fuel Ratio Variation of Cylinder) stored. To better understand the cause of this condition, AHM would like to collect specific parts from the vehicle prior to you attempting a repair of any kind.