How to pass every test we cover
A written guide for all 81 certification tests — what's actually on the exam, the topics worth your time, the traps that cost good techs points, and a study plan that fits around a work week.
Written by a working tech. Free to read, no signup.
ASE Automobile
9 tests
How to pass the A1 (Engine Repair) test
Half of A1 happens before you ever pull a head. That is where techs lose it.
How to pass the A2 (Automatic Transmission / Transaxle) test
High stall RPM means slipping clutches. Low stall means the stator. Miss that, miss A2.
How to pass the A3 (Manual Drive Train & Axles) test
Pinion depth sets the pattern, carrier shims set backlash. Mix those up and A3 ends you.
How to pass the A4 (Suspension & Steering) test
A4 fails techs who can measure a ball joint but cannot read a tire.
How to pass the A5 (Brakes) test
A5 fails techs who can do brakes but can't read a proportioning valve question.
How to pass the A6 (Electrical / Electronic Systems) test
Most A6 failures aren't theory problems. They're techs who never loaded the circuit.
How to pass the A7 (Heating & Air Conditioning) test
High head pressure is not always an overcharge. A7 asks that one five different ways.
How to pass the A8 (Engine Performance) test
A8 does not ask what a P0171 means. It asks what you do about it.
How to pass the A9 (Light-Vehicle Diesel Engines) test
Most A9 failures aren't diesel gaps. They're gas-engine habits applied to a diesel.
ASE Medium / Heavy Truck
9 tests
How to pass the T1 (Gasoline Engines) test
17-21 in-Hg steady at idle. If you cannot read the needle, T1 will eat you alive.
How to pass the T2 (Diesel Engines) test
T2 fails techs who can pull an injector but cannot explain what the cutout test proved.
How to pass the T3 (Drive Train) test
If you cannot explain clutch brake squeeze without looking it up, T3 will find that hole.
How to pass the T4 (Brakes) test
If your fix for oil in the air tanks is a new dryer, T4 is going to eat you alive.
How to pass the T5 (Suspension & Steering) test
T5 fails techs on frame rails and dual matching, not kingpins.
How to pass the T6 (Electrical / Electronic Systems) test
Ohms on a dead cable prove nothing. T6 is won with voltage drops taken under load.
How to pass the T7 (HVAC) test
Both gauges reading low is not always low charge. That question sinks people on T7.
How to pass the T8 (Preventive Maintenance Inspection (PMI)) test
Most techs fail T8 on the numbers, not the wrenching: 4/32, 2 psi, 60 psi, 2 inches.
How to pass the L2 (Electronic Diesel Engine Diagnosis) test
L2 isn't a diesel test, it's a data test - and the composite booklet decides your score.
EVT Fire Apparatus
11 tests
How to pass the DO1 (Driver/Operator Inspection) test
Most DO1 washouts aren't wrenching mistakes — they're operators who skip the air-brake check because 'it built up fine.'
How to pass the F1 (Maintenance, Inspection & Testing) test
Half the F1 room misses the vacuum test because they think 22 in. Hg has to hold.
How to pass the F2 (Design & Performance Standards) test
F2 is open book. Techs still fail it - because they cannot find the answer in time.
How to pass the F3 (Fire Pumps & Accessories) test
Most F3 failures aren't hydraulics. They're the transfer valve and the packing gland.
How to pass the F4 (Fire Apparatus Electrical Systems) test
The 11.8 V floor and a 120-second timer fail more apparatus than any bad alternator.
How to pass the F5 (Aerial Fire Apparatus) test
Most F5 misses are not hydraulics. They are the load chart with the waterway flowing.
How to pass the F6 (Allison Automatic Transmissions) test
First range and reverse both slip, everything else is fine. That's C5, not the pump.
How to pass the F7 (Foam Systems) test
Most F7 misses come from mixing up proportioning percentage with expansion ratio - they are not the same thing.
How to pass the F8 (Hydraulic Systems) test
F8 rewards the tech who remembers that a load that drifts down is a valve problem - not a pump problem.
How to pass the FA4 (Advanced Electrical Systems) test
FA4 separates the parts-changers from the diagnosticians: multiple dead functions plus a data-link fault is a bus problem, not five coincidences.
How to pass the GL (Ground Ladder Testing) test
GL is a judgment test: a darkened heat-sensor label means remove-and-test, not replace-the-label.
EVT Ambulance
5 tests
How to pass the E0 (Maintenance, Inspection & Testing) test
E0 does not fail techs on exotic stuff. It fails them on 4/32, 9.6 volts, and 20 percent.
How to pass the E1 (Ambulance Design & Performance) test
KKK-A-1822 is dead. If you still quote Rev F numbers, E1 will bury you.
How to pass the E2 (Ambulance Electrical Systems) test
Most techs don't fail E2 on lightbars. They fail on shoreline, load shed, voltage drop.
How to pass the E3 (Ambulance HVAC) test
E3 fails techs who can diagnose a car A/C but have never touched a roof condenser.
How to pass the E4 (Cab, Chassis & Powertrain) test
E4 does not fail techs on engines. It fails them on idle, voltage, and weight.
EVT ARFF (Airport)
3 tests
How to pass the AR1 (ARFF — Design & Performance (A-1)) test
AR1 starts with why an ARFF rig is built to sprint: response-time performance drives the whole design.
How to pass the AR2 (ARFF — Chassis & Components (A-2)) test
AR2's theme: an ARFF rig ages by the calendar, not the odometer.
How to pass the AR3 (ARFF — Extinguishing Agent Systems (A-3)) test
AR3 is about the agents: know which one goes on the fire, and how the truck actually throws it.
ASE Advanced & EV
4 tests
How to pass the L1 (Advanced Engine Performance) test
L1 does not ask what the code means. It asks why the code is there.
How to pass the L3 (Light-Duty Hybrid / EV) test
L3 is not an electrical test with a hybrid chapter. It is a power-flow test with electrical questions.
How to pass the L4 (ADAS (Driver Assistance)) test
The scan tool says "calibration complete." That does not mean the radar is aimed.
How to pass the XEV (High-Voltage EV Safety) test
400 V does not care that the dash says OFF. Verify zero energy or don't touch it.
EPA A/C Certification
1 test
ASE Transit Bus
8 tests
How to pass the H1 (Transit Bus — CNG Engines) test
CNG sits at 3600 psi. H1 cares more about the regulators than the engine.
How to pass the H2 (Transit Bus — Diesel Engines) test
A regen will never burn ash. That one fact is worth several questions on the H2.
How to pass the H3 (Transit Bus — Drive Train) test
H3 is not a truck test. Retarder logic and TCM inputs fail more techs than clutches.
How to pass the H4 (Transit Bus — Brakes) test
If your fix for a long pushrod is cranking the slack adjuster, H4 will fail you.
How to pass the H5 (Transit Bus — Suspension & Steering) test
A transit bus leaning at the curb is a leveling valve until you prove otherwise.
How to pass the H6 (Transit Bus — Electrical / Electronic) test
On a multiplexed bus the switch isn't a switch, it's an input. H6 punishes techs who forget it.
How to pass the H7 (Transit Bus — HVAC) test
H7 fails techs on the roof unit, not the dash: unloaders, reheat, and charging by weight.
How to pass the H8 (Transit Bus — PM Inspection) test
H8 is not a brake test. It is a paperwork test with brakes in it.
ASE School Bus
7 tests
How to pass the S1 (School Bus — Body & Special Equipment) test
Most S1 misses are not body work. They are the door switch, the transfer relay, and grounds.
How to pass the S2 (School Bus — Diesel Engines) test
Half the S2 low-power questions aren't the turbo. They're restriction you never measured.
How to pass the S3 (School Bus — Drive Train) test
The clutch brake is for launching from a dead stop, not for shifting. S3 will ask.
How to pass the S4 (School Bus — Brakes) test
S4 fails techs who crank an automatic slack adjuster to "fix" a long-stroke chamber.
How to pass the S5 (School Bus — Suspension & Steering) test
Half of S5 is steering, and half of that is knowing the gear is not what is loose.
How to pass the S6 (School Bus — Electrical / Electronic) test
Most S6 failures are not the 8-lamp system. They are voltage drop and bad grounds.
How to pass the S7 (School Bus — HVAC) test
Front vents blow cold, rear blows warm. S7 lives in the half of the bus behind you.
ASE Truck Equipment
3 tests
How to pass the TE1 (Truck Equipment — Installation) test
Most TE1 failures are not electrical. They are a payload calculation nobody bothered to run.
How to pass the TE2 (Truck Equipment — Electrical Install) test
TE2 fails techs who can splice but cannot calculate voltage drop on a 40-foot chassis run.
How to pass the TE3 (Truck Equipment — Auxiliary Power) test
Flow makes speed. Pressure makes force. Half of TE3 is that one sentence.
ASE Alternate Fuels
1 test
ASE Collision Repair & Refinish
5 tests
How to pass the B2 (Collision — Painting & Refinishing) test
B2 is not a spray test. Most guys fail it on mixing math and surface prep.
How to pass the B3 (Collision — Non-Structural Repair) test
On B3 the metal tells you the repair. Guess the steel grade and you fail the question.
How to pass the B4 (Collision — Structural Repair) test
If you cannot read a set of centering gauges, B4 ends you in the first 20 questions.
How to pass the B5 (Collision — Mechanical & Electrical) test
B5 fails techs who can panel-beat but cannot read a wiring diagram.
How to pass the B6 (Collision — Damage Analysis & Estimating) test
Most B6 failures aren't damage analysis. They're the P-pages nobody reads.
ASE Maintenance & Light Repair
1 test
Cummins
7 tests
How to pass the CX15 (X15 / ISX15 Heavy-Duty) test
FC 415 with 50 psi on a mechanical gauge is a sensor fault, not a bearing fault.
How to pass the CX12 (ISX12 / X12) test
The X12 will fail you on a shared 5-volt short, not on how well you know the XPI pump.
How to pass the CMR (B6.7 & L9 Mid-Range) test
Mixing up B6.7 and L9 valve lash sinks more techs on CMR than any hard question.
How to pass the CFUEL (XPI Common-Rail Fuel) test
Unplug the fueling actuator and rail pressure climbs. That pump isn't your problem.
How to pass the CATS (Aftertreatment & Emissions) test
A refractometer reading of 32.5% does not prove the DEF is good. That one fails techs.
How to pass the CELEC (Electrical & Sensors) test
60 ohms across CAN High and Low is a pass. 120 ohms is half a network.
How to pass the CDIAG (INSITE & Controls) test
INSITE told you the injector is bad. INSITE is wrong. Prove it before you cut the seal.
Detroit Diesel
7 tests
How to pass the DD15 (DD13 / DD15 Heavy-Duty) test
Asymmetric turbo, no vanes. Rail pressure is not injection pressure. Start there.
How to pass the DD16 (DD16 Heavy-Duty) test
The DD16 rail lives near 900 bar. The injector amplifies the rest. Miss that, fail the test.
How to pass the DFUEL (Amplified Common-Rail Fuel) test
900 bar in the rail is normal on ACRS. Condemn the pump over it and you fail DFUEL.
How to pass the DATS (Aftertreatment / One-Box) test
A 4364 on a One-Box is almost never the outlet NOx sensor. That's the whole test.
How to pass the DDEC (DDEC Controls & DiagnosticLink) test
The MCM is fuel-cooled. Miss that on the test and you miss it in the bay too.
How to pass the DAXLE (Detroit Axles) test
DAXLE fails techs on one line: heavy truck wheel bearings finish with end play, not preload.
How to pass the DT12 (DT12 Automated Manual) test
Half the DT12 "no-shift" tickets I have seen were a 60 psi air gauge, not a bad TCU.
Reading is step one
Knowing the traps helps. Drilling them is what makes them stick. 12,000 practice questions across all 81 tests — every single answer explained.
Start your 24-hour free trial