Rank #2 in Best OBD2 Scanner 2026: 10 Ranked, and the Numbers That Don't Fit
TOPDON AD500 OBD2 Scanner, 4-System Diagnostics
Price and rating as shown on Amazon when we collected them. Both change.
The TOPDON AD500 is the second-placed scanner in this guide, at £139.99, and it is a handheld tool rather than a Bluetooth dongle: the listing gives it its own 5-inch screen, Android 11.0, a 4-core 1.5GHz processor, 2GB of RAM, 32GB of storage and a 3350mAh battery, plus a 5-year manufacturer warranty. Its headline claims are four systems (engine, ABS, SRS and transmission), six reset functions (oil, throttle adaptation, SAS, TPMS, BMS and EPB), coverage of 70+ vehicle brands and a lifetime free update. That is the point of difference against the two most-reviewed readers in this guide, whose own listings say they do not touch ABS, airbag, SRS or EPB.
Two numbers in this listing do not reconcile with each other. The body is given as 23.1cm long, 3.3cm wide and 12.7cm high, while the same listing claims a 5-inch screen — and 5 inches is 12.7cm across the diagonal, which a 3.3cm-wide body cannot hold. One of those figures is wrong and the listing does not say which. Everything on this page comes from the Amazon listing for this scanner; none of it is a test result of ours.
How those 975 ratings break down
An average hides its own shape. This is the spread behind the 4.4 stars.
Specification
Exactly as published on the Amazon listing, field for field.
| Price | £139.99 |
|---|---|
| Rating | 4.4 out of 5, from 975 ratings |
| Systems covered | Engine, ABS, SRS and transmission (4 systems) |
| Reset functions | Oil, throttle adaptation, SAS, TPMS, BMS and EPB (6) |
| Screen and operating system | 5-inch screen, Android 11.0 (as listed) |
| Item dimensions (as listed) | 23.1L x 3.3W x 12.7H centimetres |
| Updates | Lifetime free update, as stated in the listing title |
| Best Sellers Rank | 16th in OBD-II Engine System Diagnostic Tools |
What buyers actually say
Quoted from customer reviews on Amazon
Verified purchase“had a cheap OBD reader that wouldn't read a fault with my airbags. Asked a mechanic to come round and diagnose it for me, for £50, but he cancelled. but this instead, and now i'll save myself £50 everytime i need a diagnosis! Read my codes instantly, gave me indepth info on them, cleared them easily, and gives me a lot of good live data in the car”
Verified purchase“Rarely do I immediately want to leave a review. Top bit of kit for the money. Good quality, easy to set up (wifi needed). Instantly diagnosed correct problems with VW transporter (fuel filter) and also VW Polo (left front abs sensor). Easily paid for itself already. Great product.”
What it is up against
The rivals it was ranked against in Best OBD2 Scanner 2026: 10 Ranked, and the Numbers That Don't Fit.
Questions people ask
Does the TOPDON AD500 read airbag and ABS faults?
Its listing says yes. The TOPDON AD500 is described as a 4-system scanner covering engine, ABS, SRS (the airbag system) and transmission, and it can erase fault codes to switch off warning lights after a repair. That is where it parts company with the two most-reviewed readers in this guide, which state in their own listings that they do not read ABS, airbag, SRS or EPB.
What does the TOPDON AD500 cost and how is it rated?
It is listed at £139.99 and rated 4.4 out of 5 from 975 ratings. Amazon's star breakdown for this model reads 74% at five stars, 12% at four, 2% at three, 4% at two and 8% at one — those five bars add up to 100, not 975, so they are a percentage split rather than counts.
Is there a subscription for updates on the TOPDON AD500?
The listing title says the TOPDON AD500 has a "LifetimeFree Update", and nothing in the listing mentions a recurring charge or a renewal period. The bullet points do not give an end date for the free updates either.
Do I need a phone to use the TOPDON AD500?
The TOPDON AD500 is listed with its own 5-inch screen, Android 11.0, a 4-core 1.5GHz CPU, 2GB of RAM, 32GB of storage and a 3350mAh battery. No phone or companion app is mentioned anywhere in the listing.
Which cars does the TOPDON AD500 cover?
The listing says 70+ vehicle brands and 16 languages, support for the CAN FD protocol on modern vehicles including 2020+ GM and Chrysler models, and that it bypasses the FCA Secure Gateway for Chrysler, Jeep, Fiat and others.
Why do the listed dimensions of the TOPDON AD500 look wrong?
The body is given as 23.1cm long, 3.3cm wide and 12.7cm high, while the same listing advertises a 5-inch screen. Five inches is 12.7cm across the diagonal, so a 5-inch screen cannot sit inside a 3.3cm-wide body. The listing does not show which of the two figures is the mistake.
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