Cheat sheet

Red Seal 310S Automotive Service Technician Cheat Sheet

A - Common Occupational Skills

7%of exam

WHMIS 2015Hoist Safety LocksTorque-to-Yield BoltsPrecision MeasurementLOTO Procedures

B - Engine & Engine Support

18%of exam

Four-Stroke CycleCooling SystemFuel InjectionTurbochargingEmissions Control

C - Vehicle Module Communications

10%of exam

CAN BusOBD-II CodesScan ToolsModule ProgrammingNetwork Topology

D - Driveline Systems

14%of exam

Manual TransmissionsAutomatic TransmissionsCV JointsDifferentialsTransfer Cases

E - Electrical & Comfort Control

18%of exam

Ohm's LawBattery & ChargingVoltage-Drop TestingHVAC CycleWiring Diagrams

F - Steering, Suspension, Braking & Tires

18%of exam

Hydraulic BrakesABS & EBDWheel AlignmentTPMSElectric Power Steering

G - Restraint, Body & Accessories

8%of exam

SRS AirbagsBody ElectricalAccessories & TrimOccupant Restraints

H - Hybrid & Electric Vehicles

7%of exam

High-Voltage SafetyHybrid Drive ModesEV Battery PacksRegenerative Braking

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

Intake: piston downCompression: piston upPower: spark firesExhaust: piston up

No-Start Diagnosis Route

  1. Cranks but no startCheck spark and fuel(Compare both systems)
  2. No crank, no clickTest battery and ground(Voltage-drop test)
  3. Click but no crankTest starter and solenoid
  4. Starts then dies quicklyCheck fuel pressure hold
  5. Rough or no sparkScope 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

P: powertrain codesB: body codesC: chassis codesU: network codes

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

  1. P-code storedPowertrain system fault
  2. B-code storedBody system fault
  3. C-code storedChassis system fault
  4. U-code storedNetwork communication fault
  5. No communication, one moduleCheck 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

V = I x RI = V / RR = V / I

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

  1. Battery light onTest alternator output voltage(13.5 to 14.5V)
  2. Voltage below rangeCheck drive belt tension
  3. Voltage above rangeSuspect regulator overcharge
  4. Parasitic drain suspectedMeasure key-off current draw
  5. Slow crank, good batteryVoltage-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

Compressor: raises pressureCondenser: rejects heatExpansion valve: drops pressureEvaporator: absorbs heat

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: 205°CDOT 4: 230°CDOT 5.1: 260°C

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

  1. Pedal sinks slowlyCheck master cylinder bypass
  2. Pedal feels spongyBleed air from lines
  3. Pedal pulses while brakingCheck rotor thickness variation
  4. ABS light with pedalScan wheel-speed sensors
  5. Pedal hard, no stopCheck 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: front tiltCaster: side tiltToe: top view angle

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

  1. Before HV serviceDon Class 0 gloves
  2. Gloves confirmed onRemove HV service disconnect(Follow LOTO steps)
  3. Disconnect removed fullyWait manufacturer discharge time
  4. Wait time completeVerify zero volts with meter(CAT III meter required)
  5. Zero volts confirmedProceed 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. 1.125 questions, four-option multiple choice
  2. 2.70% passing score required
  3. 3.Up to four hours allowed
  4. 4.Electrical domain is 18%
  5. 5.Steering/brakes domain is 18%
  6. 6.Stoichiometric ratio is 14.7 to 1
  7. 7.CAN bus reads 60 ohms
  8. 8.DOT 4 boils hotter than DOT3
  9. 9.Battery load test needs 9.6V
  10. 10.Charging voltage reads 13.5-14.5V running
  11. 11.TTY bolts always get replaced
  12. 12.HV service needs Class 0 gloves
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