Vehicle Diagnostic System Quiz

M2A3 BFV Master Gunner's Course - Sustainment and Diagnostics

• This course covers sustainment and diagnostics for the M2A3/M3A3 Bradley Fighting Vehicle (BFV).

Sustainment and Diagnostics (S&D)

• NBIT (Non-Interactive Built-In Test) is abortable.

Terminal Learning Objective

• Action: Maintain a M2A3/M3A3 Bradley Fighting Vehicle (BFV).
• Conditions: Given classroom instruction, a student guide, TM 9-2350-438-10, a fully operational M2A3 BFV, and a M2A3 desktop trainer.
• Standards: Maintain a M2A3/M3A3 BFV through sustainment and diagnostics on a BFV IAW student guide, TM 9-2350-438-10.

Learning Step Activity 1

• Action: Describe the component functions of the Power Management/Distribution Subsystem (PMDS).
• Conditions: Given classroom instruction, student guide, TM 9-2350-438-10 (31 MAY 2018), a fully operational M2A3 BFV, and a M2A3 desktop trainer.
• Standards: Student will describe the component functions of the PMDS IAW the student guide, TM 9-2350-438-10 (31 MAY 2018).

Engine Compartment Components

• Reduced White Smoke Engine (600-HP)
• 400 Ampere Generator
• Transmission
• Electronic Controlled Braking (TEC-ECB)
• Interface Assembly

Learning Step/Activity 1: Describing the PMDS

• Reduced White-Smoke Engine: Equipped with a reduced white-smoke engine. Step Timing Control (STC) cuts in within 25 seconds after engine start, reducing white smoke.
• 400 Ampere Generator: Provides regulated +28 VDC power to charge the turret reserve, turret electronics, and hull batteries.
• TEC Transmission - Electronic Controlled Braking: Consisted of Transmission, Interface Assembly (IA), Interface Cable, Electronics Assembly (EA), and the Bradley Shift Tower (BST). The EA controls the transmission via the gear selector signals.

Learning Step/Activity 1: Bradley Shift Tower

• The BST is located on the driver's right side.
• The EA is attached under the BST monitoring lever position using an interface cable (IC) to the interface assembly (IA) on the transmission.

Learning Step/Activity 1: Engine Start

• 1. Master Power to ON.
• 2. Check the light on the BST(Bradley Shift Tower) and ensure flashing. Contact maintenance if not flashing.
• 3. Move the Engine Accessory to ON. Engine and Transmission low oil light will flash until engine starts.
• 4. Push the fuel cut-off handle in.
• 5. Push the handle on the BST to the right to start the engine.
• 6. After engine start, check the engine and transmission gauge on the DTD (Driver Tactical Display).
• 7. Check the light on the top of the BST to ensure the light turns off within 22 seconds. Contact maintenance if still on.

Learning Step/Activity 1: Vehicle and Turret Batteries Viewgraph

• 24-VDC Turret Reserve Battery
• Hull Batteries (4)
• Turret Electronics Batteries (2)

Learning Step/Activity 1: Digital Vehicle Distribution Box (DVDB)

• Degraded Drivers Switch
• Emergency Turret Shutdown Switch
• DVDB distributes power to the following LRUs and electrical systems:
• Cold Start Distribution Box
• Smoke Generator Solenoid
• Ramp Pump Motor and Door Switch
• Hull Ventilation Fans
• Bilge Pumps (4)
• Fire Suppression System
• Winterization Kit (when installed)
• Emergency Shutdown Switch
• Fuel Pumps (4)
• Engine Sensors
• Driver's Instrument Panel Gages
• Hull Dome Lights and Exterior Lights
• Gas Particulate Filter Unit Pre-cleaner and Hull System
• Personnel Heater
• Hydraulic Engine Access Door
• Slave Start System

Learning Step/Activity 1: Hull and Turret Power Boxes

• Hull Power Box (HPB): Controls, distributes, protects, and isolates the power to all PCMs by an isolation circuit, has a Normal/Override switch. Disables Emergency Shut Down switches when in Override.
• Turret Power Box (TPB): Protects and distributes high-current turret loads that aren't controlled by PCM#1 and PCM#2. Receives power from hull, generator, and turret battery, and distributes that power.

Learning Step/Activity 1: Power Control Modules (PCMs)

• The PCMs distribute power to electronic components in the vehicle.
• There are two PCMs in the turret and one in the hull.
• The PCMs provide functionalities, including Load Switching, No Load Status, On/Off Status, Overload Protection, Short Circuit Protection, Grnd/Open outputs, 28-Volt/Open inputs, Built-in Test, Mil-Std 1553 Data Bus Interface, and On Board Reprogramming.

Learning Step/Activity 1: Turret Processor Unit (TPU)

• TPU is the primary mission computer.
• It takes over as the Bus Controller after power-up.
• The TPU houses the Fire Control Processor card, which controls super elevation and kinematic lead.
• The TPU stores information in its volatile and non-volatile memory, including Fire Control, Navigation, and all built-in tests (BIT) data from Test Management Diagnostic Equipment (TMDE).

Learning Step/Activity 1: Slip Ring (SLR)

• Provides interconnection for power, signal, video signals, and CBRN air connection between hull and turret.

Learning Step Activity 2

• Action: Describe the PMDS mode of operation and types of built-in tests (BITs).
• Conditions: Given classroom instruction, student guide, TM 9-2350-438-10 (31 MAY 2018), a fully operational M2A3 BFV, and a M2A3 desktop trainer.
• Standards: Description will include identification of the operating modes of operation and a description of the built-in test for the embedded diagnostic system.
• Power Up Sequence
• Power Down Sequence
• Controlled Power Down
• Uncontrolled Power Down
• Silent Watch State

Learning Step/Activity 2: Modes of Operation and Types of BITs

• Power Up Sequence: Turning on the TURRET POWER switch enables power through the HPB to the PCMs and TPB, Power to TPU, GCU, SINCGARS, EPLRS, VIS, PNS, BCIS, SCB, and then SBIT.
• Controlled Power Down: Moving the TURRET POWER switch to OFF initiates the power down.
• Uncontrolled Power Down: Uncontrolled power down is caused by an unknown failure of the turret or vehicle power.
• Silent Watch State: A low-power/low signature state that minimizes emissions. The system shuts down power to certain LRUs.
• Emergency Turret Shutdown Switch: Enables the GNR or BC to shut down turret power in case of emergencies.

Learning Step/Activity 2: Data Deletion Switch

• Permanently erases data stored in the TPU, INU, BIT, boresight, and alignment constants, and DAGR encryption keys and coordinates.

Learning Step/Activity 2: Silent Watch State

• A low-power, low-signature system state, minimizing acoustic, thermal, and electromagnetic emissions.
• The system saves data and then cuts power to LRUs including the Position Interface Box (PIB), Eye Safe Laser Rangefinder (ELRF), Gun Control Unit (GCU), Global Positioning System (GPS), Inertial Navigation Unit (INU), Gas Particulate Filter Unit (GPFU) and Heaters, Turret Drive Control Unit (TDCU), IBAS Defogger, TDS Drive power, MRE Heater, Squad Leader's Display (SLD), Driver's Displays and, Drivers Viewer Enhancer (DVE) if used.

Learning Step/Activity 3

• Action: Describe the Failure Handling Process.
• Conditions: Given classroom instruction, student guide, TM 9-2350-438-10 (31 MAY 2018), a fully operational M2A3 BFV, and a M2A3 desktop trainer.
• Standards: Student will describe the Failure Handling Process IAW the student guide.

Learning Step/Activity 3: Failure Handling Process

• Critical Failures: Limit failures to only those that compromise system safety (e.g. weapon firing, turret motion).
• Safe Mode: Transitions the fire control system to a Safe Mode when critical failures occur. Inhibits the Turret Drive System and overrides the safe to fire condition.
• Fault Handling Messages: Some LOSS messages do not automatically put the system into Safe Mode. Some advisory messages will not put the system into Safe Mode.

Learning Step/Activity 3: Accessing Malfunction Advisory

• The Commander can access this screen via the status bar MAL indicator or the SETUP/ADVSY soft-keys.
• Identifies losses of mission capability (LOSSes) and separates each loss with a semi-colon (;).
• Includes advisory messages (ADVSYs).
• Displays an advisory screen without a corresponding LOSS message.
• Identifies malfunctions (MALF faults).
• Provides a scroll bar for navigating through the MAL.

Learning Step/Activity 3: Status Terms Definitions

• GO: Fully functional and ready for use
• DEGRADED: Some functions unavailable.
• IN PROGRESS: Mission capability is undergoing BIT.
• ABORT NBIT: Uncertain whether the system is functioning fully or if there are any degrading issues.
• VERIFY: Fault not corrected in the previous power cycle; details are stored.
• NO GO/UNAVAILABLE: Fully degraded; only in degraded mode.

Learning Step/Activity 4

• Action: Identify the embedded Mission Checklists and Readiness Tests.
• Conditions: Given classroom instruction, student guide, and a M2A3 desktop trainer.
• Standards: Answer all questions correctly when questioned by the instructor.

Learning Step/Activity 4: Accessing Mission Checklists

• Pre-Mission Checklist: Verifies vehicle configurations prior to mission start
• During Mission Checklist: This can be used during the mission to check different capabilities.
• Post-mission checklist: Checks vehicle configurations at the conclusion of a mission.
• Clear Mission Checklist Memory: Used after the checklist is complete.

Learning Step/Activity 4: Readiness Test

• The Readiness Test is an automated sequence that checks the integrity of selected vehicle functions.
• The test may continue even if faults are detected.
• Initial conditions need to be correctly established.

Learning Step/Activity 4: Power Management

• Allows the crew to reset circuit breakers using the CTD.
• Identifies "tripped" states in the PCMs or TPB circuit breakers.
• Enables the operator to follow a path to reset circuit breakers: SETUP > POWER MGMT.

Learning Step/Activity 5: VDMS Architecture

• Function of the VDMS: The VDMS software resides in the TPU and comprises five types of BITs (Startup BIT (SBIT), Non-interactive BIT (NBIT), Background BIT (BBIT), Interactive BIT (IBIT), and Fault Isolation Test (FIT)).
• VDMS Use: Used for troubleshooting the system/subsystems during maintenance/repair
• This covers the procedures for initializing the vehicle diagnostics management system (VDMS), various forms of interactive components involved, and how to interpret the information displayed.

Learning Step/Activity 5: Fault Isolation Test (FIT)

• Used only by trained maintainers.
• Isolates failed mission critical components.
• Isolates failed non-mission-critical components.