NHTSA ID Number: 10232325
Manufacturer Communication Number: LI14.30-N-075882
TSB/Document Date: 2023-03-03
Summary
Complaint Check engine warning light active. Fault code P300CA8 or P300CA9 "Hot film mass air flow sensor malfunction" is present in engine control unit. Cause a) In the case of fault P300CA8: • Due to incorrectly installed component parts of the clean air line between the air filter box and the exhaust gas turbocharger, it is possible that leaks may occur in the system which subsequently result in air mass faults • A fouled air filter or leaks in the intake or charge air system downstream of the exhaust gas turbocharger may also cause these faults. b) In the case of fault P300CA9: • Computational model for programmed values of air intake, in particular, for the high load mode, calculates this high load correction programmed value incorrectly. This leads to the programmed value drifting too quickly towards the limit. Remedy Install the following add-ons: 18937 for XENTRY 12/2020 18938 for XENTRY 03/2021
Check engine warning light active - fault P300CA8 and P300CA9 "Hot
film mass air flow sensor malfunction" present in engine control unit
Topic number
LI14.30-N-075882
Version
1
Function group
14.30 - Secondary air injection
Date
2/3/23
Validity
Model 907 with engine 654
Reason for change
Remedy adjusted
Complaint
Check engine warning light active.
Fault code P300CA8 or P300CA9 "Hot film mass air flow sensor malfunction" is present in engine control unit.
Cause
a) In the case of fault P300CA8:
•
•
Due to incorrectly installed component parts of the clean air line between the air filter box and the exhaust gas
turbocharger, it is possible that leaks may occur in the system which subsequently result in air mass faults
A fouled air filter or leaks in the intake or charge air system downstream of the exhaust gas turbocharger may also cause these faults.
b) In the case of fault P300CA9:
•
Computational model for programmed values of air intake, in particular, for the high load mode, calculates this
high load correction programmed value incorrectly. This leads to the programmed value drifting too quickly
towards the limit.
Remedy
Install the following add-ons:
18937 for XENTRY 12/2020
18938 for XENTRY 03/2021
a) In the case of fault P300CA8:
Check correct installation of individual parts of clean air line between exhaust gas turbocharger and air filter box.
03.02.2023 17:22:00
© Copyright Mercedes-Benz
AG
MARCGU
Page 1 / 7
In particular check connection between exhaust gas turbocharger and right-hand clean air line and between righthand clean air line and center clean air line which has a connector coupling.
Relevant area of exhaust gas turbocharger to right-hand clean air line (Picture 1a):
Check that right-hand clean air line is correctly aligned with exhaust gas turbocharger.
For a single-stage turbocharger, the cast lug must be cleanly aligned with the counterpart profile (see Picture 1b).
For a two-stage turbocharger, the cast lug must be cleanly aligned with the tab (see Picture 1c).
When carrying out repair and installation work, replace the seal in this area.
Relevant area of right-hand clean air line to center clean air line (connector coupling - Picture 2a):
Observe the following operation steps:
•
•
•
•
Operate connector coupling as far as end stop rib (open position). See Picture 2b.
Hold connector coupling open until left-hand clean air line is pushed into the connector coupling as far as the
end stop and lies flush all round. See Picture 2c
Release connector coupling and actively slide it back to the closed position.
Check correct seating of clean air line using the lock position. If the lock position is not visibly reached as in Picture 2d, the clean air line must be repositioned.
See also WIS Media: AR09.10-D-8130TSM and AR09.40-D-0500TSM
For example images of good and poor installation, see Picture 3 and Picture 4.
After this, work through the guided test in XENTRY Diagnosis and read out the intake system's correction values.
If the intake system is mechanically sound, reset the programmed values for the intake system.
Please make sure that the programmed values are at zero after being reset. To do so, check the actual values.
It is not necessary to create a TIPS case.
b) In the case of fault P300CA9:
The confirmed abnormal behavior of the adapted air path used for calculation of the learned value, means that a software update will now be made available for the engine control unit. This is currently still in the approval process.
Attachments
File
Description
2b.JPG
03.02.2023 17:22:00
© Copyright Mercedes-Benz AG
MARCGU
Page 2 / 7
2c.JPG
1c.JPG
03.02.2023 17:22:00
© Copyright Mercedes-Benz AG
MARCGU
Page 3 / 7
1b.JPG
2a.JPG
1a.JPG
2d.JPG
03.02.2023 17:22:00
© Copyright Mercedes-Benz AG
MARCGU
Page 4 / 7
3.JPG
4.JPG
03.02.2023 17:22:00
© Copyright Mercedes-Benz AG
MARCGU
Page 5 / 7
5.JPG
WIS-References
Document number
Title
Note
AR09.40-D-0500TSM
Remove/install air intake line upstream of exhaust gas turbocharger
Symptoms
Power generation > Engine management > Indicator lamp > Engine diagnosis > lit
Control unit/fault code
Control unit
Fault text
N3/40 - Motor electronics 'MRD1' for combustion engine
'OM654' (CDI) (MRD1NFZ)
P300CA9 - The air mass flow in the intake air system (cylinder bank 1) has a malfunction.
P300CA8 - A leak was detected in the intake air system.
Operation numbers/damage codes
Op. no.
Operation text
03.02.2023 17:22:00
© Copyright Mercedes-Benz AG
Time
MARCGU
Damage
code
Note
Page 6 / 7
03.02.2023 17:22:00
© Copyright Mercedes-Benz AG
MARCGU
Page 7 / 7
- Formulated for engines with 75,000 miles or more, Valvoline...
- Delivers 20% better wear protection and 15% better sludge...
- Extra detergents safeguard against friction, corrosion and...
- Advanced friction-fighting additives help maximize...
- Provides performance benefits for high mileage, new and...
Last update on 2026-06-23 / Affiliate links / Images from Amazon Product Advertising API
If the PDF is very large, it may not load in the preview below.
Some older TSBs had multiple PDFs — visit the NHTSA Website to view all PDFs.
If the TSB PDF does not show, download or view it on the NHTSA Website.
Click on the (+) Plus Sign
Then Click on Associated Document(s)
Search NHTSA Database for Recalls
Search NHTSA Database for Vehicle Investigations
View Latest Vehicle Investigations
Search NHTSA Database for Vehicle Complaints
View Latest Vehicle Complaints
TSB/Document ID: LI14.30-N-075882
Replacement Service Bulletin Number:
MFR Communication Date: 2023-02-03
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: ENGINE AND ENGINE COOLING
MFR Component System:
MFR Component Subsystem:
Previous TSB | Next TSB |
- [Notice] When you receive a used device, it may be a customer return resold by Amazon without inspection. You can exchange it for a new one through Amazon. As this situation is unavoidable, we sincerely apologize. For any issues, contacting us via Amazon's "Messages" is the best way. THINKSCAN 689BT Bidirectional Scan Tool Can Be Used Immediately After It is Turned On, Without Complicated Registration Process, Which is More Convenient & Quick.
- Full Bi-Directional Control & 3000+ Active Tests: Take control and test components like actuators, fuel injectors, relays, and cooling fans in real time. You’ll quickly see if the problem is in the part itself or the control module — saving you hours of guesswork and frustrating trial-and-error.
- Advanced ECU Coding Capabilities: Handle module matching and hidden feature activation with confidence. When you replace an ECU or want to customize settings, this obd2 scanner diagnostic bi directional tool gives you the professional-level capabilities you need without the dealership price tag.
- 34+ Useful Reset and Maintenance Functions: Complete everyday service tasks smoothly with a wide range of helpful reset and maintenance functions. Whether you’re keeping up with regular upkeep or tackling a specific job, this scanner makes maintenance simpler and less stressful for both DIYers and pros.
- Comprehensive Full System Diagnostics: Diagnose every major system — Engine, Transmission, ABS, SRS, TPMS, and more — all in one place. Finally stop wondering if you’re missing something important; get the full picture and clear codes with ease.
Last update on 2026-07-02 / Affiliate links / Images from Amazon Product Advertising API
- Top Reasons to Choose the D7S OBD2 Scanner: XTOOL D7S car scan tool, an upgrade of XTOOL D7, offers comprehensive features for automotive technicians, workshops, and DIY enthusiasts 1. Upgraded Hardware: 2+64GB memory, rear camera, intuitive interface, foldable bracket 2. Complete Diagnostics: FCA
Autoauth, OE-level all system scan, 39+ maintenance services, 4K+ bidirectional, CANFD/DoIP protocol 3. Advanced Capabilities: ECU c0ding, PMI functions 4. Wide Compatibility: Support 10,000+ models, covering 99% vehicle brands 5. Multi-language: Available in 22+ languages, No IP Restrictions 6. 3-Year Updates: Save 300 bucks on software updates for the latest features and optimizations - 2026 Upgraded D7S Car Scanner Features: The newly 2026 D7S V2.0 scanner for car brings exciting features for advanced vehicle diagnostics and enhanced user experience 1. FCA AutoAuth: Now supports FCA SGW module for Chrysler, for Jeep, for Dodge (2018+), for Fiat (2017+), enabling faster vehicle communication without gateway restrictions 2. PMI (Offline ECU Pr0gramming): Allows for Ford, for Lincoln, and for Mazda ECU pr0gramming for new modules 3. Optimized Diagnostic Report 2.0: Personalized reports with logos and customer info for auto shops. Note: Compatibility varies by cars, please check before order
- 39+ Services/Resets/Adaptations/Relearns/Calibrations: XTOOL D7S full system car scanner diagnostic tool tackles 99% of common car issues through its 36+ special functions, including Oil Reset, EPB, SAS, BMS, Throttle Reset, Injector C0ding, ABS Bleed, TPMS Reset, Power Balance, etc and also covers specific-vehicle functions like Crank Sensor Relearn, ABS Initialization, Cylinder Power Balance, Fuel Trim Reset, Idle Relearn etc. This car diagnostic scanner enhances efficiency, making repairs and maintenance hassle-free. Tip: DO NOT for All vehicles, please check compatibility first
- Cost-effective ECU C0ding Scan Tool for Specific Brands: Enhance your vehicle's performance with XTOOL D7S! This obd2 scanner all systems bidirectional offers advanced capabilities at an affordable price, supports online for BMW, for Benz and offline for BENZ, for MIT, along with PMI functions for Ford, for Mazda, and for Lincoln. Ideal for technicians and DIY enthusiasts, this automotive scanner diagnostic tool optimizes vehicle performance and enhances the driving experience. Note: Not for all cars and modules, please send car VIN to check the compatibility before purchase
- OE All System Diagnostic & 8 Pids Graphing: XTOOL D7S is a comprehensive all system bi directional obd2 scanner that delivers dealer-level diagnostics, completely controlling over your vehicle’s performance and health. This automotive scan tool can read and clear DTCs, view live data and ECU information, retrieve freeze frames, and perform active tests and full obd2 functions. This bi-directional scan tool can can identify your vehicle's make, model, and year information with just one click and show up to 8 PIDs live data with options for CSV viewing, playback, and recording for in-depth analysis. It is easy-to-use for both professionals and beginners, helping pinpoint issues efficiently
Last update on 2026-07-08 / Affiliate links / Images from Amazon Product Advertising API
- 【✅Compared to BOSSCOMM IF742, IF745 Offers Full-System Diagnostics】The BOSSCOMM IF745 car diagnostic scanner is an upgraded model of IF742. In addition to supporting all OBD2 Code Reader functions and 6 reset options (ABS/EPB/SAS/BMS/Oil/Throttle), it expands diagnostics from 4 systems (Check Engine/ABS/SRS/Transmission) to vehicle All systems, including Steering, Suspension, and Body Electronics. This provides deeper, more comprehensive diagnostic capabilities.
- 【✨10 OBD2 Functions】The BOSSCOMM IF745 scan tool’s DTC Lookup instantly translates fault codes into user-friendly explanations, its I/M Readiness feature streamlines emissions testing with a single tap, and Freeze Frame lets you pinpoint the exact moment of a fault for in-depth root-cause diagnosis. Combined with a live data dashboard and advanced diagnostics (O2S, OBMon, EVAP), it delivers comprehensive insights for confident troubleshooting.
- 【✨Deep Diagnostics for All Vehicle System Modules】Beyond code reading/clearing and ECU information retrieval, our all-in-one data stream feature lets you inspect all current fault codes and their locations across the vehicle’s systems. This vehicle code reader helps you turn off dashboard warning lights and perform a comprehensive self-check of your car at home—no more back-and-forth trips to the repair shop or hefty inspection fees.
- 【✨6 Essential Resets: ABS Bleeding, Oil, EPB, SAS, Throttle, BMS】The BOSSCOMM IF745 obd2 scanner diagnostic tool swiftly purges air from brake lines to restore braking sensitivity, fine-tunes maintenance cycles to eliminate false alerts, resolves parking brake issues with one-click control, recalibrates steering sensors for stability, optimizes engine idling/acceleration for smoother performance, and deeply resets battery systems to extend lifespan and range via precise parameter adjustments.❗NOTE: Does NOT support bidirectional control, coding, or programming.
- 【✨10,000+ Car Models, AutoVIN, 13 Languages】The BOSSCOMM IF745 vehicle scanner diagnostic tool covers 73+ global car brands and offers support in 13 languages, making it perfect for DIYers, auto mechanics, or as a thoughtful gift. With a single-click AutoVIN feature, it instantly retrieves vehicle serial numbers, streamlining diagnostics for users globally. This adaptable tool balances user-friendliness with precision, catering to both personal and professional requirements.✅Unsure about compatibility? Compatibility will vary on vehicles' model and year, pls reach us via 📧 [email protected] 📧 before purchase.
Last update on 2026-07-02 / Affiliate links / Images from Amazon Product Advertising API
This product presentation was made with AAWP plugin.