Instant Digital Download  ·  HTML + Printer-Friendly PDF  ·  270 Sheets
You Changed the Part.
The Light Didn’t Care.
Welcome to the club.
Now let’s find out why it came back.
Professional-grade OBD-II diagnostic reference sheets written from 20 plus years of real shop experience — for anyone who needs the right answer fast, without digging through a service manual.
PARTS CANNON 3000
Professional Technicians Apprentices Shop Foremen Service Writers Fleet Managers Shop Owners Serious DIY Vehicle Enthusiasts
Digital Download
Category Packs — from $19.99
Every sheet in one system — Misfire, Fuel, ABS, Transmission and more. One zip with every code in the category, each as an HTML sheet and a printer-friendly PDF.
Instant download  ·  HTML + PDF  ·  $19.99 / $29.99 / $39.99
Best Value
Master Library — $119.99
All 270 sheets across all 19 systems in a single download. Every pack, every code — the complete reference for your shop or garage.
Instant download  ·  HTML + PDF  ·  All 270 sheets
Shop All Sheets See a Sample No subscription. No account needed. Instant download. Prices in USD.
270
Sheets
19
System Categories
20+
Years Experience
2
Formats: HTML + PDF
What You Get
Everything on one sheet
No hunting through service manuals. No forum rabbit holes. Every sheet covers one OBD-II code — completely.
Most common causes
Ranked by real-world frequency with percentage bars — so you always know where to start and what to check first.
Diagnostic flowchart
A step-by-step decision tree so you always know the next test to run — no guessing, no going in circles.
Pro tips and gotchas
The stuff a 20-plus-year tech knows that the scanner won’t tell you — misdiagnoses, misleading readings, what to check before you order parts.
Reference data table
Normal vs. failed readings for every test component — actual numbers so you can confirm or rule out a fault fast.
Safety warnings
Critical warnings per code — high voltage, SRS, fuel pressure, and anything else that can hurt you if you get it wrong.
Related codes
Which codes commonly show up together and why — never chase one fault while missing the root cause hiding behind it.
Scope waveforms
Normal vs. fault patterns on the codes where a scope is the right tool — so you know what the trace should look like before you hook up.
Printer-friendly PDF
Every sheet also comes as a PDF laid out like a service-manual page. Print it, laminate it, pin it to the bay wall.
The Library
Browse by system
Every sheet is colour-coded by system — grab the right one at a glance whether you’re at the bay, the desk, or the driveway.
Misfire
18 sheets
Fuel System
27 sheets
O2 Sensors
26 sheets
EVAP
11 sheets
ABS
16 sheets
Transmission
14 sheets
CAN Bus
19 sheets
A/C System
8 sheets
Air Intake / Turbo
25 sheets
Timing / VVT
16 sheets
EGR
8 sheets
Diesel
16 sheets
Electrical
13 sheets
EV / Hybrid
8 sheets
Catalyst
3 sheets
Engine Cooling
5 sheets
Throttle Control
8 sheets
SRS / Airbag
16 sheets
Reference
13 sheets
Written by a tech.
Built for everyone.
These sheets come from 20 plus years of real diagnostic work — not textbooks, not forums. Every cause is ranked the way an experienced tech actually thinks about a code.
Read the full story  →
  • 20 plus years of hands-on shop experience behind every sheet
  • Causes ranked by frequency — the way a real tech approaches a code
  • Plain language — no service manual jargon
  • Designed to be printed, not just read on a screen
  • Always growing — new codes added regularly