A - Common Occupational Skills
7%of exam
B - Engine & Engine Support
18%of exam
C - Vehicle Module Communications
10%of exam
D - Driveline Systems
14%of exam
E - Electrical & Comfort Control
18%of exam
F - Steering, Suspension, Braking & Tires
18%of exam
G - Restraint, Body & Accessories
8%of exam
H - Hybrid & Electric Vehicles
7%of exam
Quick Facts
- Exam
- Red Seal 310S
- Questions
- 125 MCQ
- Time
- Up to 4 hours
- Format
- Four-option multiple choice
- Pass
- 70%
- Fee (Ontario)
- ~$150 + HST
- Retake (Ontario)
- 30-day wait
- Sponsorship
- Not required
Shop Safety & PPE
- Class B fire
- Flammable liquids fuel
- Class C fire
- Energized electrical equipment
- WHMIS 2015
- Aligned with GHS
- LOTO
- Locks out hazardous energy
- Hoist safety locks
- Engage before going under
- EV glove class
- Class 0, 1000V rated
Fasteners & Measurement
- Torque-to-yield bolt
- Single-use, always replace
- Micrometer resolution
- 0.001 inch or 0.01mm
- SDS
- 16-section hazard reference sheet
- Used oil
- Approved recycling program only
- Torque sequence
- Follow manufacturer specified pattern
Four-Stroke Order
Intake, Compression, Power, Exhaust in that order
No-Start Diagnosis Route
- Cranks but no start→Check spark and fuel(Compare both systems)
- No crank, no click→Test battery and ground(Voltage-drop test)
- Click but no crank→Test starter and solenoid
- Starts then dies quickly→Check fuel pressure hold
- Rough or no spark→Scope ignition waveform
Engine Fundamentals
- Four-stroke order
- Intake, compression, power, exhaust
- Compression ratio
- BDC volume over TDC volume
- Thermostat opens
- About 195°F / 90°C
- Cooling boost
- Each psi adds ~3°F boil
- 5W-30 oil
- 5W cold flow, 30 hot
- TDC
- Top dead center
Fuel, Ignition & Cooling
- Stoichiometric ratio
- 14.7 to 1 air-fuel
- Closed-loop control
- PCM targets stoich ratio
- Common-rail diesel
- High-pressure direct injection
- Turbocharger
- Exhaust-driven forced induction
- Firing order
- Cylinder ignition sequence
- Radiator cap
- Raises coolant boiling point
Emissions Control Systems
- Three-way catalyst
- Oxidizes CO/HC, reduces NOx
- EGR valve
- Recirculates exhaust, lowers NOx
- EVAP system
- Traps fuel vapor, charcoal canister
- PCV valve
- Recycles crankcase blow-by gas
- O2 sensor
- Reads exhaust oxygen content
- DPF
- Traps diesel particulate matter
DTC Prefix Guide
P engine, B body, C chassis, U network
P0300 vs P0301 Code
P0300
- Random multiple misfire
- Not cylinder-specific
- Broad diagnosis needed
P0301
- Cylinder 1 misfire
- Cylinder-specific code
- Targeted diagnosis
Random vs cylinder-specific code
DTC & Network Fault Route
- P-code stored→Powertrain system fault
- B-code stored→Body system fault
- C-code stored→Chassis system fault
- U-code stored→Network communication fault
- No communication, one module→Check CAN bus resistance(Should read 60 ohms)
Networks & Scan Tools
- CAN bus resistance
- 60 ohms, ignition off
- CAN terminator
- Two 120-ohm resistors parallel
- Bidirectional scan tool
- Commands actuators for testing
- Module programming
- Flashes updated software calibration
- Network topology
- How modules interconnect wiring
OBD-II Trouble Codes
- P-code
- Powertrain system fault
- B-code
- Body system fault
- C-code
- Chassis system fault
- U-code
- Network communication fault
- Freeze frame
- Sensor snapshot at fault
- P0300
- Random multiple-cylinder misfire
Open vs Limited-Slip Differential
Open diff
- Equal torque split
- Allows cornering speed difference
- Stuck if one spins
Limited-slip
- Clutch packs resist difference
- Sends torque to traction
- Better in low traction
LSD resists one-wheel spin-out
Clutches & Manual Transmissions
- Clutch function
- Disconnects engine from transmission
- Synchronizer
- Matches gear speed before engaging
- Friction disc
- Clamped between flywheel, pressure plate
- Dog teeth
- Engage after synchronizing speeds
Manual/Auto vs CVT Transmission
Manual/Auto
- Fixed gear steps
- Synchronizers or planetary gears
- Discrete ratio changes
CVT
- Variable pulley diameters
- Belt or chain drive
- Infinitely variable ratio
Fixed steps vs stepless ratio
Automatic Transmissions & CVT
- Torque converter
- Fluid coupling multiplies torque
- Lock-up clutch
- Locks impeller to turbine
- Planetary gearset
- Sun, planet, ring members
- CVT ratio
- Variable-diameter pulleys, steel belt
Driveline & Differentials
- Open differential
- Equal torque, unequal speed
- Limited-slip diff
- Clutch packs resist wheel spin
- CV joint
- Constant velocity at steering angle
- Transfer case
- Splits power to both axles
- U-joint
- Speed varies at large angles
Ohm's Law Triangle
V equals I times R always
Series vs Parallel Circuits
Series
- Same current everywhere
- Voltage divides across loads
- One path only
Parallel
- Same voltage everywhere
- Current divides by branch
- Multiple paths
Same current vs same voltage
Charging System Fault Route
- Battery light on→Test alternator output voltage(13.5 to 14.5V)
- Voltage below range→Check drive belt tension
- Voltage above range→Suspect regulator overcharge
- Parasitic drain suspected→Measure key-off current draw
- Slow crank, good battery→Voltage-drop starter circuit
Electrical Fundamentals
- Ohm's law
- V equals I times R
- Power formula
- P equals V times I
- Series circuit
- Same current, split voltage
- Parallel circuit
- Same voltage, split current
- Voltage-drop test
- Finds resistance in live circuit
- Ground symbol
- Return path to battery negative
A/C Cycle Order
Compress then condense expand then evaporate
R-134a vs R-1234yf
R-134a
- Higher GWP ~1430
- Non-flammable A1
- Older standard refrigerant
R-1234yf
- GWP under 1
- Mildly flammable A2L
- Current new-vehicle standard
Lower GWP but mildly flammable
Battery & Charging Specs
- Charged battery voltage
- About 12.6V open circuit
- Specific gravity
- About 1.265 fully charged
- Battery load test
- 9.6V minimum at 70°F
- Alternator output
- 13.5 to 14.5V running
- Parasitic draw limit
- About 25-50 milliamps normal
HVAC & Comfort Control
- A/C cycle order
- Compress, condense, expand, evaporate
- R-1234yf
- GWP under 1, mildly flammable
- TXV/orifice tube
- Meters refrigerant, drops pressure
- Blend door
- Mixes heated, cooled cabin air
- Refrigerant recovery
- Never vent, always recover
DOT Fluid Boiling Order
DOT 3 lowest, 4 higher, 5.1 highest boil
DOT 3 vs DOT 4
DOT 3
- 205°C dry boil
- Glycol-based
- Lower cost
DOT 4
- 230°C dry boil
- Glycol-based
- Higher performance
Higher number means higher boil
Soft Brake Pedal Route
- Pedal sinks slowly→Check master cylinder bypass
- Pedal feels spongy→Bleed air from lines
- Pedal pulses while braking→Check rotor thickness variation
- ABS light with pedal→Scan wheel-speed sensors
- Pedal hard, no stop→Check booster vacuum supply
Hydraulic Brakes & Fluid
- Pascal's law
- Pressure transmits equally, all directions
- DOT 3 fluid
- 205°C / 401°F dry boil
- DOT 4 fluid
- 230°C / 446°F dry boil
- DOT 5.1 fluid
- 260°C / 500°F dry boil
- Bleeding sequence
- Farthest wheel first, diagonal split
Alignment Angle Memory
Camber tilts, caster leans, toe points
Camber vs Caster
Camber
- Tilt viewed from front
- Affects tread wear
- Vertical wheel angle
Caster
- Tilt viewed from side
- Affects steering stability
- Steering axis angle
Camber wears, caster stabilizes
ABS, EBD & Sensors
- Passive ABS sensor
- Magnet, coil, analog signal
- Active ABS sensor
- Hall-effect, digital, reads to zero
- EBD
- Varies front-rear brake force
- Brake fluid hazard
- Hygroscopic, absorbs moisture over time
- Wheel-speed sensor code
- Triggers ABS or traction fault
Active vs Passive ABS Sensor
Passive
- Variable-reluctance magnet coil
- Analog AC signal
- Fails at low speed
Active
- Powered Hall-effect element
- Digital output signal
- Reads down to zero
Active reads down to zero
Alignment, Tires & TPMS
- Camber
- Front-view wheel tilt, tread wear
- Caster
- Side-view steering axis tilt
- Toe
- Leading-trailing edge distance difference
- Thrust angle
- Rear axle versus centerline angle
- TPMS trigger
- 25% below placard pressure
- Electric power steering
- Motor assists, no hydraulic pump
Restraint & Body Systems
- SRS system
- Airbags, seatbelt pretensioners together
- Crash sensor
- Triggers airbag deployment threshold
- Body control module
- Manages lighting, locks, windows
- Occupant classification
- Detects seat occupant, weight sensor
- Accessory trim
- Non-structural interior/exterior components
12V vs High-Voltage System
12V system
- Standard lead-acid battery
- Powers accessories and starter
- Orange cables not used
HV system
- Battery pack up to 400V+
- Orange high-voltage cables
- Requires Class 0 gloves
Orange cable means high voltage
Hybrid/EV Service Safety Route
- Before HV service→Don Class 0 gloves
- Gloves confirmed on→Remove HV service disconnect(Follow LOTO steps)
- Disconnect removed fully→Wait manufacturer discharge time
- Wait time complete→Verify zero volts with meter(CAT III meter required)
- Zero volts confirmed→Proceed with HV repair
Hybrid & EV Systems
- HV glove class
- Class 0, 1000V rated
- Service disconnect
- Isolates high-voltage battery pack
- Regenerative braking
- Motor recovers energy, slows vehicle
- HV cable color
- Orange indicates high voltage
- Discharge wait time
- Follow manufacturer capacitor discharge spec
- CAT III meter
- Required for HV voltage verification
Common Traps
P-code vs U-code
P is powertrain fault ≠ U is network fault
Camber vs Caster Effect
Camber causes tread wear ≠ Caster affects steering stability
DOT Fluid Number Confusion
Higher number is not thicker ≠ Higher number means higher boil
CAN Bus Resistance Reading
60 ohms is healthy reading ≠ 120 ohms means missing resistor
TTY Bolt Reuse
TTY bolts are single-use ≠ Always replace, never reuse
Stoichiometric Ratio Direction
14.7:1 is air to fuel ≠ Not fuel to air ratio
R-1234yf Flammability
R-1234yf is mildly flammable ≠ Needs dedicated recovery equipment
Misfire Code Specificity
P0300 is random multiple ≠ P030X is cylinder specific
Last Minute
- 1.125 questions, four-option multiple choice
- 2.70% passing score required
- 3.Up to four hours allowed
- 4.Electrical domain is 18%
- 5.Steering/brakes domain is 18%
- 6.Stoichiometric ratio is 14.7 to 1
- 7.CAN bus reads 60 ohms
- 8.DOT 4 boils hotter than DOT3
- 9.Battery load test needs 9.6V
- 10.Charging voltage reads 13.5-14.5V running
- 11.TTY bolts always get replaced
- 12.HV service needs Class 0 gloves
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