Permis de Conduire Catégorie E — Ensembles Routiers (Mali)

What is the primary function of the fifth wheel (sellette d'attelage) mounted on the chassis of a semi-trailer tractor?

• ATo connect the tractor to the semi-trailer kingpin while allowing articulated articulatio…
• BTo lock the tractor and trailer into a rigid, non-pivoting frame for highway stability
• CTo provide direct hydraulic power from the tractor engine to the trailer drive axles
• DTo serve strictly as an emergency towing attachment in case of a drawbar fracture

What is the kingpin (cheville ouvrière) on a semi-trailer?

• AA heavy steel vertical pin projecting beneath the front apron plate of the semi-trailer t…
• BA pneumatic valve located on the rear axle that balances air pressure between brake chamb…
• CA mechanical hand crank used exclusively to raise and lower the trailer landing legs
• DAn electrical multi-pin connector that powers trailer indicator lights and ABS circuits

What is the purpose of conducting a 'tug test' (test de traction) immediately after coupling a tractor to a semi-trailer?

• ATo verify mechanically that the fifth wheel locking jaws have fully closed and secured ar…
• BTo measure the maximum fuel consumption rate of the tractor under maximum throttle load
• CTo calibrate the electronic speedometer and odometer before entering the highway
• DTo test whether the trailer cargo has exceeded the authorized gross combination weight (P…

Why do heavy semi-trailer landing gears (béquilles) feature a two-speed gearbox?

• ALow gear provides mechanical advantage to raise a loaded trailer, while high gear allows…
• BLow gear is used only for highway travel, while high gear is used when parking on steep d…
• CLow gear operates the left landing leg, while high gear operates the right landing leg in…
• DHigh gear connects the landing gear directly to the tractor engine power take-off (PTO)

On drawbar trailers equipped with safety chains, why must the chains be crossed beneath the drawbar (timon d'attelage)?

• ATo form a cradle that catches the drawbar and prevents it from digging into the road surf…
• BTo increase the steering angle of the trailer when negotiating sharp city street corners
• CTo shorten the electrical ground return path for trailer clearance lighting
• DTo allow the trailer to automatically decouple itself if trailer roll exceeds 45 degrees

Where must the landing gear crank handle (manivelle) be placed after the landing legs are fully retracted?

• ASecured firmly in its designated retaining clip or stowage hook on the trailer chassis
• BLeft hanging downward freely to facilitate emergency access during quick stops
• CRemoved and placed inside the tractor cabin sleeper berth behind the driver
• DTied with a rope to the rear wheel mudflap of the tractor unit

Before backing a tractor under a parked semi-trailer to couple, what should the driver verify regarding the trailer wheels?

• AThat the trailer parking brakes are locked and wheel chocks (cales de roue) are placed ag…
• BThat all trailer tyres are deflated to half their normal pressure to lower trailer height
• CThat the trailer wheels are completely free to roll so the trailer can absorb the tractor…
• DThat the trailer axle leaf springs are disconnected from their mounting shackles

What visual inspection must a driver conduct under the fifth wheel after completing the mechanical coupling and tug test?

• ALook underneath with a flashlight to verify that the locking jaws are closed completely a…
• BVerify that the trailer tyres are touching the bottom of the tractor mudguards
• CEnsure that there is a visible 5-centimetre gap between the fifth wheel top plate and the…
• DConfirm that the red emergency air hose has been routed directly through the fifth wheel…

When positioning the tractor fifth wheel beneath the semi-trailer apron plate during coupling, what is the correct initial contact height?

• AThe trailer apron plate should be slightly lower than the fifth wheel centre, so the fift…
• BThe trailer apron plate must be at least 15 centimetres higher than the fifth wheel so th…
• CThe fifth wheel top plate should be tilted forward toward the tractor cab to catch the fr…
• DThe trailer landing gear must be raised off the ground before the tractor enters the trai…

What is the danger of attempting to couple a tractor to a semi-trailer when the trailer is set too high on its landing gear?

• AThe kingpin can ride over the top of the fifth wheel jaws, resulting in an uncoupled trai…
• BThe red pneumatic emergency line will spontaneously pressurize to 20 bar and rupture
• CThe tractor rear tyres will immediately burst from excessive vertical downforce
• DThe steering angle of the tractor front axle will become mechanically locked in reverse

What occurs during a 'high hitch' (attelage haut), where the fifth wheel locking jaws lock around the head of the kingpin instead of the shank?

• AThe coupling is unstable and the kingpin can easily slip out of the jaws under load, caus…
• BThe tractor suspension will automatically raise to its maximum off-road height setting
• CThe trailer brakes will lock permanently and cannot be released by air pressure
• DThe kingpin will permanently weld itself to the fifth wheel jaws through friction

When uncoupling a loaded semi-trailer on hot asphalt, soft unpaved ground, or gravel, what precaution must be taken with the landing gear feet?

• APlace solid wooden or steel spreader plates (bastaings ou cales de répartition) beneath t…
• BLubricate the landing gear feet with liquid grease so they slide freely over the surface
• CDeflate all trailer tyres completely so the landing gear carries zero trailer load
• DDisconnect the cross-shaft connecting the left and right landing legs

What is the correct standard sequence for disconnecting lines and mechanisms when uncoupling a semi-trailer from a tractor?

• ASecure vehicle with brakes and chocks, lower landing gear, disconnect and stow air/electr…
• BRelease fifth wheel lock, drive tractor forward 1 metre, disconnect lines, then wind down…
• CDisconnect air lines, pull fifth wheel release handle, drive away, and let the trailer se…
• DLower landing gear, remove kingpin with a blowtorch, then disconnect tractor battery

Why should the driver lower the landing gear until the feet contact the ground and then give several additional turns in low gear before pulling the fifth wheel release handle?

• ATo relieve excess downward pressure from the trailer apron onto the fifth wheel, allowing…
• BTo stretch the pneumatic air hoses so they disconnect automatically without human interve…
• CTo lift the trailer completely clear of the tractor frame by at least 30 centimetres
• DTo engage the trailer's automatic mechanical anti-theft steering lock

What is the function of the secondary safety latch (cran ou linguet de sécurité) on a fifth wheel release handle?

• ATo prevent accidental unlatching of the fifth wheel release handle caused by vehicle vibr…
• BTo enable the driver to uncouple the trailer while driving at highway speeds in an emerge…
• CTo automatically apply the trailer service brakes whenever the tractor engine is turned o…
• DTo lock the tractor steering wheel in the straight-ahead position during coupling

When reversing a road train combination with a full trailer equipped with a turntable steer axle (avant-train tournant), what device is often used to assist in straight-line reversing?

• AA turntable lock (verrouillage de tourelle / dispositif de blocage de l'avant-train)
• BAn automatic trailer engine accelerator pedal
• CA pneumatic pressure release valve that empties all tractor tyres
• DAn electronic radar that automatically steers the drawbar without driver input

Why must heavy-duty grease (or an approved Teflon friction plate) be maintained on the fifth wheel top surface plate?

• ATo minimize rotational friction between the fifth wheel and trailer apron, preventing ste…
• BTo seal the kingpin from electrical lightning strikes during wet season thunderstorms
• CTo keep the kingpin from rotating inside the fifth wheel locking jaws
• DTo increase friction so the semi-trailer resists turning in curves

When connecting pneumatic air hoses between tractor and trailer, why must the rubber glad hand seals (joints d'accouplement) be inspected?

• AWorn, cracked, or missing rubber seals will cause compressed air leaks, potentially trigg…
• BThe seals generate hydraulic pressure to lubricate the kingpin locking jaws
• CThe rubber seals serve as electrical resistors that regulate brake light voltage
• DDamaged seals will cause diesel fuel to contaminate the pneumatic air dryer

If the fifth wheel release handle cannot be pulled out when attempting to uncouple, what is the recommended procedure?

• AGently ease the tractor backward against the trailer with trailer brakes locked to reliev…
• BStrike the release handle with a heavy sledgehammer until the locking mechanism breaks op…
• CAccelerate forward in high gear at full throttle to snap the locking jaws free
• DDrain all air from the tractor suspension and tyre reservoirs until the frame drops to th…

What is the function of the trailer bolster/apron plate (plaque de frottement) located on the underside of the semi-trailer front?

• ATo provide a smooth, flat structural bearing surface that rests upon and slides over the…
• BTo protect the trailer cargo from heat generated by the tractor exhaust silencer
• CTo act as a mounting bracket exclusively for the front license plate and road tax disc
• DTo store spare compressed air for the trailer emergency brake booster

How should a driver assess longitudinal play between fifth-wheel locking jaws and the kingpin?

• ACheck it using the coupling manufacturer's inspection method and wear limit; excessive pl…
• BUp to 25 millimetres to permit dynamic movement during emergency braking
• CExactly 50 millimetres to allow trailer roll in tight roundabouts
• DZero millimetres, requiring hydraulic press-fitting every time the vehicle couples

When coupling a tractor unit equipped with electronically controlled pneumatic suspension (ECAS), what is the correct handling of the suspension height?

• AUse the cab/chassis remote control to lower the suspension, back partially under the trai…
• BRaise the tractor suspension to its maximum height before reversing to force the trailer…
• CCompletely bleed the air bags to the bump stops and leave them deflated during highway dr…
• DKeep the suspension in off-road mode at 80 km/h to maintain elevated fifth wheel clearance

In an automatic drawbar coupling system (chape d'attelage automatique avec axe), how does the driver verify that the coupling pin has locked securely?

• ACheck that the mechanical visual indicator pin (témoin de verrouillage) has dropped flush…
• BListen for a loud pneumatic whistle from the exhaust tailpipe
• CConfirm that the trailer drawbar eye is resting on top of the towing pin without touching…
• DMeasure the electrical resistance of the drawbar safety chains with a multimeter

If a driver must uncouple a loaded semi-trailer on a slight gradient, what specific chocking and braking sequence is critical to prevent runaway or equipment damage?

• AChock the trailer wheels on the downgrade side, verify trailer spring brakes are applied,…
• BDisconnect air lines first so the trailer slides down the hill until it finds natural bal…
• CLower landing gear directly onto the sloped ground without wheel chocks and release the f…
• DPlace wheel chocks only under the tractor front steering tyres and leave trailer wheels u…

How should wear on a trailer kingpin be evaluated during inspection?

• AUse the specified go/no-go gauge and replace the kingpin when it exceeds the coupling or…
• BA diameter reduction of 15.0 millimetres
• CAny discoloration of the paint on the bottom face of the kingpin head
• DWhen the kingpin length increases by more than 10 centimetres

In a standard dual-line commercial vehicle pneumatic braking system, what color designates the supply/feed line (conduite d'alimentation)?

• ARed
• BYellow
• CBlue
• DGreen

In a standard dual-line commercial vehicle pneumatic braking system, what color designates the control/service line (conduite de commande)?

• AYellow
• BRed
• CBlack
• DOrange

What is the primary function of the emergency breakaway braking feature on a towed trailer?

• ATo automatically apply the trailer brakes at maximum force if the trailer accidentally di…
• BTo automatically deploy a parachute behind the trailer during emergency stops
• CTo divert engine coolant into the brake drums to cool them down during high-speed stops
• DTo disconnect the trailer axles and allow the wheels to roll independently into the ditch

What is the role of the engine-driven air compressor (compresseur d'air) in a heavy combination vehicle?

• ATo pump atmospheric air into storage reservoirs to create and replenish compressed air fo…
• BTo pump compressed air directly into the tyres while driving on the highway
• CTo blow cool air into the driver cab for air conditioning
• DTo generate exhaust backpressure to increase engine acceleration

What component removes moisture and oil droplets from the compressed air before it reaches the vehicle storage tanks?

• AThe air dryer (dessiccateur d'air / cartouche déshydratante)
• BThe radiator fan shroud
• CThe fuel water separator filter
• DThe exhaust particulate filter

How are spring parking brakes (cylindres à ressort / Tristop) held in the released position during normal driving?

• ABy continuous compressed air pressure acting against a powerful mechanical coil spring
• BBy an electric electromagnet powered constantly by the vehicle alternator
• CBy hydraulic fluid pumped directly from the power steering reservoir
• DBy mechanical tension cables pulled by the driver foot pedal

Why must compressed air storage tanks (réservoirs d'air) be drained regularly using their manual drain valves?

• ATo expel accumulated water and oil condensation that can corrode tanks, degrade brake val…
• BTo reduce vehicle gross weight by draining heavy air molecules
• CTo refill the engine cooling system with fresh condensed moisture
• DTo allow ambient dust into the air lines to increase friction on the brake shoes

If the red supply line between the tractor and semi-trailer ruptures while driving at 70 km/h on a highway, what will occur?

• AThe rapid loss of supply air causes the trailer emergency relay valve to instantly apply…
• BThe trailer will freewheel without any brakes while the tractor accelerates automatically
• CThe tractor engine will instantly shut down and lock the steering column
• DThe yellow control line will automatically convert into a diesel fuel line

What happens if the yellow control line ruptures or disconnects while driving, and the driver subsequently presses the service brake pedal?

• AThe tractor brakes will work, but the trailer service brakes will receive no control sign…
• BThe tractor engine will immediately explode from compressed air backpressure
• CThe trailer will automatically steer itself into the oncoming traffic lane
• DThe entire electrical system of the vehicle will blow all fuses instantly

What is 'brake lag' (temps de réponse pneumatique) in a long combination vehicle, and how should a driver compensate for it?

• AThe delay while a pneumatic brake command builds at remote brake chambers; compensate by…
• BThe delay caused by the driver closing their eyes during heavy panic braking maneuvers
• CThe time required for the air conditioning compressor to disengage during passing maneuve…
• DThe time delay between shifting from high range to low range in the auxiliary transmission

What is the function of a relay valve (valve relais) installed on the chassis of a semi-trailer near the trailer axles?

• ATo accelerate trailer brake application and release by feeding air directly from the near…
• BTo transmit radio signals from the trailer cargo doors to the driver smartphone
• CTo convert 24-volt electrical current from the tractor into 12-volt current for trailer l…
• DTo mix diesel fuel additives automatically into the trailer axle wheel bearings

In road transport regulations, what is the legal definition of 'continuous braking' (freinage continu) for an articulated vehicle combination?

• AA system controlled by a single driver control that applies coordinated braking simultane…
• BA braking system that operates non-stop 24 hours a day even when the vehicle is parked an…
• CA brake that uses a continuous stream of water sprayed onto tyre treads during highway dr…
• DA system where the trailer brakes are engaged continuously while the tractor engine is ru…

What is the purpose of an automatic load-sensing valve (correcteur de freinage asservi à la charge / ALSV) on a trailer axle?

• ATo automatically adjust braking air pressure in proportion to the trailer's actual cargo…
• BTo automatically pump fuel from the tractor into the trailer when carrying heavy cargo
• CTo calculate transport freight charges based on axle deflection
• DTo raise the trailer roof pneumatically when cargo volume increases

If a disabled trailer has zero air pressure and its spring parking brakes are locked, how can they be mechanically released for emergency towing?

• ABy manually unwinding the mechanical release bolt (vis de desserrage / caging bolt) at th…
• BBy cutting the rubber brake lines with a pocketknife to release trapped vacuum
• CBy heating the brake drums with a blowtorch until the metal expands
• DBy hitting the tyres with a heavy sledgehammer to dislodge the brake shoes

What severe hazard is created if a driver uses an independent trailer hand brake lever (manette de frein de remorque) to slow down on a slippery downgrade?

• AThe trailer wheels can easily lock up while the tractor rolls freely, initiating a violen…
• BThe tractor engine will overheat instantly and seize the pistons
• CThe fifth wheel will automatically uncouple the kingpin
• DThe trailer suspension air bags will immediately explode

When may a driver depart after starting a combination vehicle with a low-air warning active?

• AOnly after pressure reaches the vehicle manufacturer's operating range, the warning extin…
• BAt exactly 1.0 bar (14.5 psi)
• CAt 18.0 to 20.0 bar (260 to 290 psi)
• DAt 0.2 bar (3 psi)

What is the function of a one-way check valve (clapet anti-retour) installed in the pneumatic charging circuit?

• AIt allows air to flow into a reservoir but prevents it from flowing backward if upstream…
• BIt allows air to escape freely into the cab to cool down the driver
• CIt prevents fuel from entering the brake shoes during refuelling
• DIt restricts vehicle speed to 30 km/h whenever cargo exceeds 10 tonnes

During a pre-trip inspection, how can a driver verify that the trailer's automatic emergency breakaway brake is operational?

• ADisconnect the red emergency supply line while parked with tractor running, and confirm t…
• BDrive at 90 km/h on the highway and uncouple the fifth wheel while in motion
• CTurn off the tractor headlights and check if the trailer hazards flash
• DOpen the engine oil filler cap and listen for an air hiss

When disconnecting pneumatic hoses during uncoupling, what should the driver do with the loose glad hand couplings on the tractor?

• AConnect them securely to the tractor's dummy storage couplings (supports borgnes / fausse…
• BAllow them to drag on the tractor chassis plate where they can drain oil onto the pavement
• CWrap them in greasy rags and place them inside the fuel filler neck
• DTie them tightly around the tractor propeller driveshaft

What is brake fade (évanouissement des freins / fading) on a long mountain descent, and how must a professional driver prevent it?

• ALoss of braking friction caused by severe overheating of brake linings and drums; prevent…
• BA loss of radio reception in mountainous areas; prevented by installing a taller antenna
• CAir leaking from tyres due to high altitude; prevented by increasing tyre pressure to 15…
• DThe brake pedal sticking to the floor due to cold weather; prevented by pouring boiling w…

In modern commercial vehicles equipped with an Electronic Braking System (EBS), what is the primary role of the CAN-bus electronic data link between tractor and trailer (ISO 7638)?

• ATo transmit rapid digital brake-control and diagnostic signals, reducing response delay w…
• BTo display video movies from the driver cabin onto the rear doors of the trailer
• CTo supply electric drive power to propel the trailer rear wheels on steep ascents
• DTo recharge the trailer battery directly from the solar panels on the tractor roof

How should the result of a static pneumatic leakage test on an articulated combination be judged?

• AAgainst the vehicle manufacturer's procedure and the applicable inspection standard, with…
• BUp to 5.0 bar per minute as long as the engine starts immediately afterwards
• CZero drop whatsoever; any drop of 0.001 bar requires total vehicle replacement
• DUp to 8.0 bar within 30 seconds