Twenty original illustrated automotive diagnostic visual sheets created specifically for Bob's Mechanical Repairs in a workshop-focused style: wiring, sensors, CAN networks and worked case studies drawn out so the system makes sense at a glance.
What the 20 diagnostic visual sheets actually cover
Volume 1 is twenty original illustrated automotive diagnostic visual sheets covering the systems that generate most of the diagnostic work in a UK independent garage: high fuel consumption, CAN bus testing, passive ABS wheel-speed sensors, front-wheel-drive layout, P0420 catalytic converters, gateway and control-unit architecture, power-window and horn relay wiring, ignition coil drivers, airbag crash sensors, fuel odour and EVAP, engine control unit wiring, electrical symbols, starting and charging circuits, temperature gauge senders, engine sensor identification, two worked CAN communication case studies, a central gateway case study and a chassis sensor diagnostic guide.
Each sheet is a single illustrated page that shows how the system is arranged and what you are looking at, so the shape of the circuit or the network makes sense before you start measuring. They are created specifically for Bob’s Mechanical Repairs in a workshop-focused style.
Why a visual cheat sheet beats a full technical manual at the ramp
Manufacturer data is authoritative but slow to read. When a car is on the ramp and the customer is waiting, what you want is the shape of the circuit, the two or three measurements that split the fault in half, and a reminder of the thing that commonly gets misdiagnosed. That is exactly what a visual cheat sheet is for.
Use the sheets to decide what to measure and in what order, then go to the manufacturer data for the exact pin numbers, wire colours and specification values for the vehicle in front of you. The two work together — the sheets are not a replacement for proper technical data and are not sold as one.
How access works after you pay
The pack is a one-off £5.99 purchase in GBP, taken through PayPal. There is no subscription and no card details are stored on our side. You give an email address purely so we can confirm the order and deliver your access link.
As soon as PayPal confirms the payment, the full pack unlocks in the same browser session and a private access link is emailed to you as well. That page holds all twenty visual sheets in a one-at-a-time viewer with a protected PDF download of the complete set. If you ever lose the link, the product page has a resend option.
Honest limitations
These are generic illustrated training aids created specifically for Bob’s Mechanical Repairs in a workshop-focused style, with any source credits shown on the sheets left intact. We deliberately do not invent vehicle-specific torque figures, resistance values or pin numbers, because a made-up number in a workshop is worse than no number at all.
There is a visible safety note with the pack. Values and procedures must be checked against exact manufacturer information, and airbag/SRS and high-voltage hybrid or electric systems must only be worked on by a competent, suitably qualified and equipped person following the correct isolation procedure.
Where the free guides fit alongside the paid pack
Our CAN bus diagnostics guide stays free and is not going behind a paywall. The same goes for the fault code lookup, the MOT failure decoder and the symptom pages. If you only need one topic, use those.
The paid pack exists for people who want breadth — twenty systems in one consistent visual reference rather than twenty separate articles — and it is presented as a workshop reference rather than as a web article.
Frequently asked questions
What exactly do I get for £5.99?
All 20 original illustrated visual diagnostic sheets in Volume 1, unlocked in your browser straight after payment and also sent to your email as a private access link, plus a branded PDF of the complete set to download. It is a one-off purchase, not a subscription.
Is this a subscription?
No. It is a single £5.99 payment for Volume 1. There is no recurring charge, and payment is handled by PayPal.
Will future volumes be included?
No. Volume 1 is 20 illustrated visual sheets. A Volume 2 is planned and would be a separate purchase if released. Buying Volume 1 does not entitle you to it.
Can I download the visual sheets as a PDF?
Yes. Your access page has a protected download button for the branded PDF of all 20 visual sheets, so you can keep an offline copy for the toolbox.
Do these replace manufacturer data?
No. They are generic training and diagnostic aids that explain how systems work and give you a sensible test order. Torque figures, resistance values, pin numbers and procedures must always be checked against the exact manufacturer information for the vehicle you are working on.
Who are the diagnostic cheat sheets for?
Working technicians wanting a fast refresher, apprentices and college students building fundamentals, MOT testers and service advisers explaining faults to customers, and competent home mechanics who are comfortable using a multimeter.
Are there vehicle-specific wiring diagrams?
No. Every sheet is a generic illustration of how that type of system or circuit works. We do not republish manufacturer diagrams or invent vehicle-specific values.
What if I lose my access link?
Use the resend option on the product page and enter the email you bought with. For privacy the response is the same whether or not an order exists, and a fresh link goes to the address on the order.