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Service bulletins for the 2018 Mazda CX-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.

470 on file from NHTSA, as of 2026-10-19.

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Only bulletins with component: Engine are shown. Show all

Bulletins, newest first
SA-035-232023-07-05. Service bulletin. ENGINE AND ENGINE COOLING. Some customers may complain of a lack of power under heavy load without any warning lights or DTCs. This concern may be due to a loose or detached hood weatherstrip, which can cause a blockage or restriction in the air intake system.
01-008-232023-07-05. Service bulletin. ENGINE AND ENGINE COOLING. Some vehicles may exhibit oil leakage from the drive belt auto tensioner and rattling noises from the engine compartment. This may be caused by insufficient sealing at the drive belt auto tensioner damper when the auto tensioner fully operates under both high ambient temperature and high load conditions. To eliminate this concern, the shape of the drive belt auto tensioner damper has been changed.
SA-032-232023-06-04. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. If you encounter any type of electrical concern (e.g, dead battery, engine no start, DTC(s) stored...), interview the customer before proceeding with normal MGSS diagnosis by asking if any aftermarket devices have been installed. Aftermarket devices may be the cause of the electrical concern. Below are a few examples of unusual electrical concerns caused by aftermarket devices.
01-002-23a2023-03-03. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold (as shown below). There may be cracks at the stud bolt hole (1) or at the outside of the exhaust manifold flange (2) on the cylinder head.
01-001-23a2023-03-03. Service bulletin. ENGINE AND ENGINE COOLING. Some customers may complain about a poor acceleration and rough idling or the CHECK ENGINE light ON with DTC P0301:00, P0302:00, P0303:00, P0304:00.NOTE: Only turbo engines are applicable; non-turbo engines are NOT applicable. In most cases, DTCs P030X stores, but sometimes not. Sometimes the CHECK ENGINE light does not recognize this engine concern. This is caused by the variable valve in the exhaust manifold seizing and causing the exhaust port to become hot and the exhaust valve seat to wear unevenly, resulting in compression leakage. To eliminate this concern, the design of the exhaust manifold has been modified.
01-002-232023-02-02. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM; ENGINE AND ENGINE COOLING. Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold (as shown below). There may be cracks at the stud bolt hole or at the outside of the exhaust manifold. Cracks may be caused by: - Deformation of the exhaust manifold during usage causing unexpected force to certain areas of the cylinder head. - Residual stress generated during production in the cylinder head material may be greater than expected. The external force from the exhaust system when driving over bumps may cause unexpected force to certain areas of the cylinder head. To eliminate this concern, the design of the exhaust manifold gasket and the cylinder head has been modified to reduce the force on the cylinder head.
01-001-232023-02-02. Service bulletin. ENGINE AND ENGINE COOLING. Some customers may complain about a poor acceleration and rough idling or the CHECK ENGINE light ON with DTC P030X:00 (only turbo engines are applicable; non-turbo engines are NOT applicable). - In most cases, P030X is stored, but sometimes not. - Sometimes the CHECK ENGINE light does not recognize this engine concern. This is caused by the variable valve in the exhaust manifold seizing and causing the exhaust port to become hot and the exhaust valve seat to wear unevenly, resulting in compression leakage. To eliminate this concern, the design of the exhaust manifold has been modified.
RF-23-012023-02-02. Service bulletin. ENGINE AND ENGINE COOLING. When servicing SKYACTIV engine vehicles requiring to replace the Oil Galley Plug and Crush Washer, order the required part numbers below. These parts are not listed in GEPC and were previously listed as "non-serviceable" in the cylinder block diagram.
MT-004-222023-01-05. Service bulletin. ENGINE AND ENGINE COOLING. Some vehicles may experience the Check Engine Light ON with DTC P0171 (Fuel Trim too Lean) and possibly DTCs P030X (Misfire). Vehicles having this concern should use the following Inspection/Repair procedure.
01-007-222022-07-06. Service bulletin. ENGINE AND ENGINE COOLING. Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold (as shown below). There may be cracks at the stud bolt hole or at the outside of the exhaust manifold. Cracks may be caused by: - Deformation of the exhaust manifold during usage causing unexpected force to certain areas of the cylinder head. - Residual stress generated during production in the cylinder head material may be greater than expected. The external force from the exhaust system when driving over bumps may cause unexpected force to certain areas of the cylinder head. To eliminate this concern, the design of the exhaust manifold gasket and the cylinder head has been modified to reduce the force on the cylinder head.
SA-018-222022-05-05. Service bulletin. ENGINE AND ENGINE COOLING. The WSM shows 3 possible crankshaft sprocket and timing chain combinations (Type A, B and C), but some vehicles have been produced with a combination of Type A timing chain with 2 yellow-colored links with a Type B crankshaft sprocket.
00-001-222022-03-04. Service bulletin. POWER TRAIN; SERVICE BRAKES, HYDRAULIC; ENGINE AND ENGINE COOLING; STEERING. Mazda has developed factory recommended scheduled maintenance services that support all major vehicle systems. Mazda recommends dealers follow the scheduled maintenance tables as cited in the vehicle-specific workshop manual or owner's manual. Services performed outside of Mazda's factory scheduled maintenance are not recommended. These services are unnecessary and create unneeded expenses for your customers.
01-013-21-3753a2022-01-06. Service bulletin. ENGINE AND ENGINE COOLING. Coolant Leaks At Cylinder Head: Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold (as shown below). There may be cracks at the stud bolt hole (1) or at the outside of the exhaust manifold (2).
09-030-21-38382021-10-31. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:ENGINE:HARD PARTS INTERNAL/MECHANICAL; EQUIPMENT ADAPTIVE/MOBILITY. Some vehicles may exhibit a rattle, clunk or pop noise from the front of the vehicle while driving. The noise may be caused by loose cowl panel bolts.
01-014-21-38402021-10-31. Service bulletin. ELECTRICAL SYSTEM:ADAS:DRIVER MONITORING:SOFTWARE; ENGINE AND ENGINE COOLING; EQUIPMENT:ELECTRICAL:ENGINE BLOCK HEATER. Some vehicles may exhibit the CHECK ENGINE light on with DTC P011B:00 (Engine coolant temperature/IAT: Correlation error) when using an engine block heater which is set up by MCI as local accessory parts. Due to variation of block heater performance and environmental conditions against the SKYACTIV-G 2.5T engine, the PCM has difficulty detecting block heater operation. To eliminate this concern, the control software of the PCM has been modified to increase the margin for the block heater detection performance to the similar level as 2019 and later models.
01-013-21-37532021-10-31. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold (as shown below). There may be cracks at the stud bolt hole (1) or at the outside of the exhaust manifold (2). Cracks may be caused by: Deformation of the exhaust manifold during usage causing unexpected force to certain areas of the cylinder head. Residual stress generated during production in the cylinder head material may be greater than expected. The external force from the exhaust system when driving over bumps may cause unexpected force to certain areas of the cylinder head. To eliminate this concern, the design of the exhaust manifold gasket and the cylinder head has been modified to reduce the force on the cylinder head.
MT-002-212021-10-02. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. Ethanol is becoming a common additive in gasoline. Gasoline containing ethanol is likely available at your local gasoline station. Typical blends of ethanol include E10 and E85. E10: A blend of 10% ethanol and 90% gasoline, E85: A blend of 85% ethanol and 15% gasoline, All Mazda vehicles can run on gasoline containing up to 10% ethanol (E10) but only some 1999-2001 B3000 trucks can run on gasoline with more than 10% ethanol blended. E10 compatible vehicles: All Mazda vehicles. E85 compatible vehicles: 1999-2001 B3000 Mazda trucks with the 8th VIN digit is V. What if a customer puts E85 in there Mazda vehicle? Symptoms include: Rough Running, Lean Codes, Misfires and/or misfire codes, Lack of power, Poor fuel economy, Spark knock, Mechanical engine damage.
01-006-21-3779a2021-09-03. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY; ENGINE AND ENGINE COOLING. This service bulletin provides testing and charging procedures in order to promote proper battery maintenance, to deliver new vehicles with fully charged batteries, and to reduce unnecessary battery replacement cost. For new vehicles in stock at the dealer, inspect and maintain the battery periodically according to the repair procedure.
01-001-21-3761a2021-08-02. Service bulletin. ENGINE AND ENGINE COOLING. Some vehicles may exhibit an occasional rough idle accompanied with DTC P0300:00 (Random misfire) due to the following: 1. While closing the EGR valve, carbon deposit etc. pinched at the valve seat prevents the valve from closing completely. 2. The closed position of the EGR valve is learned improperly as it is not equipped with a position sensor. 3. While idling, the EGR gas improperly mixes with fresh air through the EGR valve that is not closed properly. 4. Misfire occurs. To eliminate this concern, the control software of the PCM has been modified (for service) to force the learning of the closed position of the EGR valve when a misfire is detected at idle.
MT-002-212021-06-01. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. When programming a key or installing a Genuine Mazda Accessory Remote Engine Start system, you may encounter programming difficulty. This may be caused by a customer installed aftermarket decorative trim and/or cover on the START/STOP ENGINE button. The aftermarket accessory may create electrical interference, which may interfere with programming.
MT-001-212021-06-01. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING; EQUIPMENT. If you encounter any type of electrical concern (e.g, dead battery, engine no start, DTC(s) stored...), interview the customer before proceeding with normal Workshop Manual diagnosis. Aftermarket devices may be the cause of the electrical concern. Ask the customer if any aftermarket devices have been installed.
SA-072-172021-03-08. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:GAS RECIRCULATION VALVE (EGR VALVE); ELECTRICAL SYSTEM; ENGINE. If you receive a customer complaint of a Check Engine Light on with a DTC P0401 stored in memory, follow the repair procedure below.
SA-071-172021-03-08. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. The 2018 CX-9 Maintenance Monitor engine oil data reset procedure (for oil change) is different than other models due to a specification problem. It must be reset in 2 places - in MAZDA CONNECT and in the instrument cluster. It is important to reset in both places at every oil change to avoid unnecessary customer return. NOTE: If the reset procedure is not performed in both places, a maintenance message will be displayed in the instrument cluster after the customer leaves the dealer.
CSP05d2021-03-03. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. MULTI-MODEL - MAZDA MOBILE START CUSTOMER SATISFACTION PROGRAM (CSP05). As shared previously, due to planned industry-wide changes in mobile network infrastructure and wireless technology, the Mazda Mobile Start (MMS) accessory was no longer offered beginning with 20MYvehicles. These technology changes are scheduled to occur in late 2021 as our service provider transitions away from a 3G network which currently supports the MMS application and its vehicle operations for all active legacy accounts. As a result, the MMS application and its vehicle operations will no longer work after September 30. 2021 for these legacy accounts and their respective vehicle owners. In an effort to provide advance notice and be transparent, and also to lessen the inconvenience of this situation - On 11/12/2020, all active MMS account holders will be informed of this news and will be presented with their choice of one of following goodwill offers: A new, replacement remote-engine start system (key fob transmitter type), Installation of Apple CarPlay / Android Auto, A $1000 voucher towards the purchase or lease of a new Mazda vehicle
CSP05c2021-03-03. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. MULTI-MODEL - MAZDA MOBILE START CUSTOMER SATISFACTION PROGRAM (CSP05). As shared previously, due to planned industry-wide changes in mobile network infrastructure and wireless technology, the Mazda Mobile Start (MMS) accessory was no longer offered beginning with 20MYvehicles. These technology changes are scheduled to occur in late 2021 as our service provider transitions away from a 3G network which currently supports the MMS application and its vehicle operations for all active legacy accounts. As a result, the MMS application and its vehicle operations will no longer work after September 30. 2021 for these legacy accounts and their respective vehicle owners. In an effort to provide advance notice and be transparent, and also to lessen the inconvenience of this situation - On 11/12/2020, all active MMS account holders will be informed of this news and will be presented with their choice of one of following goodwill offers: A new, replacement remote-engine start system (key fob transmitter type), Installation of Apple CarPlay / Android Auto, A $1000 voucher towards the purchase or lease of a new Mazda vehicle

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.