Affiliate disclosure

Current status

We are publishing this policy before we need it, so that the rules are written down while nobody has a financial interest in bending them.

What we expect to do

A free reference site of this size has to pay for itself. We expect that to come from display advertising and from affiliate links to diagnostic tools and replacement parts — the same scanners and multimeters our diagnostic procedures already tell people to use.

When that happens, an affiliate link will be labelled as one, and this page will say which programmes we participate in.

Rules that will apply

• Commercial relationships never change diagnostic content. A cause will not move up the list, and a repair will not be recommended, because a part carries a commission. Causes are ordered by how often they are actually responsible.
• No part is recommended without a confirming test. This already applies. A code page will never say "P0135 means buy this oxygen sensor" — it will say what test would confirm the sensor has failed, and only then where to get one.
• No fabricated fitment claims. We will not tell you a part fits your vehicle unless we have fitment data good enough to stand behind. A search link is honest; a compatibility guarantee we cannot support is not.
• Advertising will not obstruct the answer. No ad above the plain-English explanation, nothing that mimics navigation, nothing that causes layout shift, and nothing positioned to collect accidental clicks.
• No fake product recommendations. We will not populate product modules with placeholder recommendations to make a page look monetised.

Why we are telling you this now

Because the failure mode is well known. Automotive content is full of pages that exist to sell a part, dressed as diagnosis, and they cause real people to spend real money replacing parts that were working. This site is built to be useful without any of that, and it should stay legible as such after the money arrives.

See also our editorial policy.