FAW Dashcam: The 3 Critical Components for Fleet Safety Revealed

Welcome to this critical technical analysis of the FAW Dashcam and logic assembly. For the FAW Jiefang CA4251P66K24T1A3E5 6×4 diesel semi-trailer tractor, this system is a mandatory, safety-critical component. It functions as the vehicle’s “black box,” more accurately described as a digital tachograph and Electronic Data Recorder (EDR). Its “logic” is to create a tamper-proof record of vehicle operation and driver activity.

The FAW Dashcam system (also known as a Tachograph) is not a single part but a “logic assembly” of three core components working in unison: the ‘Tachograph assy’ (the brain), a ‘GPS/BD antenna’ (for location), and a ‘GPRS antenna’ (for data transmission). This system is essential for fleet management, accident reconstruction, and legal compliance with driver Hours of Service (HOS) regulations.

This in-depth guide is a vital resource for fleet safety managers, technicians, and parts specialists. We will deconstruct the entire FAW Dashcam assembly into its three distinct Minimum Serviceable Units (MSUs). We will analyze the “brain” (7914010-61B-C00) and the two critical antennas that allow it to function as a complete, connected telematics and safety solution.

MSU 1: The “Black Box” Logic – ‘Tachograph assy’ (7914010-61B-C00)

This component is the “longer” and most complex part of the FAW Dashcam system. The ‘Tachograph assy’ (7914010-61B-C00) is the central processor and data recorder. It is a sealed “black box” and the primary Minimum Serviceable Unit (MSU). It is not designed to be repaired; if it fails, it must be replaced and re-programmed to the truck’s VIN.

The “logic” of this device is five-fold: data acquisition, driver management, data storage, real-time alerts, and data transmission (via the other MSUs).

1. Data Acquisition Logic (CAN Bus):

The FAW Dashcam (Tachograph) is wired directly into the vehicle’s J1939 CAN bus network. It constantly “listens” to the digital conversation between the truck’s other ECUs. It is programmed to “pull” and record specific data packets, including:

• Vehicle Speed: A continuous, second-by-second log of how fast the truck is moving.
• Engine RPM: Records engine speed, which can be used to analyze driver behavior (e.g., over-revving).
• Braking Events: Logs every time the brake pedal is pressed, and can record “hard braking” events.
• Engine Load & Fuel: Monitors fuel consumption and engine load, which is critical data for fleet efficiency analysis.

2. Driver Management Logic (HOS):

This is the tachograph’s primary legal function. The device includes a slot for a digital driver ID card. When the driver inserts their card, the FAW Dashcam logs them in. The driver must then select their status:

• Driving: Automatically set when the vehicle is in motion.
• On-Duty (Not Driving): e.g., loading, unloading, vehicle inspection.
• Off-Duty / Sleeper Berth: The driver is resting.

The tachograph creates an official, tamper-proof Electronic Driver Log (EDL) to ensure compliance with Hours of Service (HOS) laws, preventing driver fatigue.

3. Data Storage & Security Logic:

All this data is stored in a robust, internal, tamper-proof solid-state memory. This “black box” logic is crucial for accident reconstruction. In the event of a crash, this MSU can be recovered and the data (speed, braking, driver status in the seconds before impact) can be analyzed. This data is encrypted and protected from alteration.

4. Serviceability (MSU):

As a sealed electronic module, the ‘Tachograph assy’ is the main MSU. A failure can manifest in several ways: failure to read driver cards, inability to communicate with the CAN bus, or “bricked” internal memory. A technician will run a diagnostic scan. If the unit is unresponsive and its power/ground connections are good, the entire FAW Dashcam unit is replaced.

MSU 2: The Location Logic – ‘GPS/BD antenna assy’ (7903070-61B-C00)

This is the second component of the FAW Dashcam assembly. The ‘GPS/BD antenna assy’ is a dedicated antenna that provides the “where” and “when” for all the data the tachograph records.

The “Logic” of Geolocation: This antenna is a high-sensitivity receiver for Global Navigation Satellite Systems (GNSS). “GPS” refers to the American system, and “BD” refers to Beidou, the Chinese system. This MSU provides the ‘Tachograph assy’ with two critical pieces of data:

• Precise Location: It pinpoints the truck’s latitude and longitude.
• Atomic Clock Time: It provides a universal, time-stamped signal.

This data is what makes the FAW Dashcam (Tachograph) logs verifiable. It’s not enough to know the driver drove for 8 hours. The system must prove *where* they drove and at *what time* they started and stopped. This MSU provides that proof.

Serviceability (MSU): This antenna is a passive MSU. It has no moving parts. Failures are almost always physical: a damaged coaxial cable (pinched or cut), a corroded connector, or improper mounting (e.g., placing it under a metal object, blocking its view of the sky). If the FAW Dashcam reports a “GPS signal loss” fault, this antenna or its cable is the MSU to inspect.

MSU 3: The Telematics Logic – ‘GPRS antenna assy’ (7903060-61B-C00)

This is the third and final piece of the FAW Dashcam system. The ‘GPRS antenna assy’ is the “voice” of the assembly. It is the cellular antenna.

The “Logic” of Transmission: GPRS (General Packet Radio Service) is a cellular data technology. This antenna allows the ‘Tachograph assy’ (which contains a cellular modem and SIM card) to connect to the internet over the mobile phone network.

This “logic” is what transforms the FAW Dashcam from a simple *recorder* into a *telematics device*. This is what allows the fleet manager to track the truck in real-time. This antenna transmits all the data the tachograph is logging—location, speed, HOS status, and fault codes—directly to the fleet’s server.

Serviceability (MSU): Like the GPS antenna, this is a passive MSU. It is a simple antenna designed to send and receive cellular signals. A failure here (damaged cable, poor ground, bad location) will result in the FAW Dashcam appearing “offline” to the fleet manager. The unit will still be recording data locally (a “store-and-forward” logic), but it will be unable to transmit it until this antenna’s connection is restored.

FAW Dashcam Logic Assembly Parts List

The following table provides the complete, detailed breakdown of all 3 component types identified in the FAW Dashcam (Tachograph) assembly for the FAW CA4251P66K24T1A3E5 tractor.

Technical Specifications and Assembly Context

The specifications for the FAW Dashcam assembly are defined by its function as a legal, connected, and tamper-proof digital tachograph system. It is a 3-part telematics solution.