








🚗 Unlock your car’s secrets with pro-level diagnostics in your pocket!
The TOPDON AL400 is a mid-range OBD2 scanner offering 10 full diagnostic functions including engine code reading/clearing, O2 sensor and EVAP tests, and I/M readiness checks. Compatible with most US, EU, and Asian cars since 1996, it features a bright 2.4-inch color screen, supports 7 languages, and provides free lifetime software updates. Designed for both DIYers and professionals, it’s compact, easy to use, and backed by 24/7 customer support and a 24-month warranty.

















| ASIN | B09XD1FGWM |
| Batteries | 1 Lithium Polymer batteries required. |
| Best Sellers Rank | 9,173 in Automotive ( See Top 100 in Automotive ) 100 in OBD-II Engine System Diagnostic Tools |
| Brand | TOPDON |
| Customer Reviews | 4.2 4.2 out of 5 stars (2,190) |
| Date First Available | 7 April 2022 |
| Item Weight | 410 g |
| Item model number | AL400 |
| Manufacturer | TOPDON |
| Manufacturer part number | AL400 |
| Model | AL300/400/500B |
| Product Dimensions | 7.9 x 2.43 x 14.7 cm; 410 g |
K**N
Worth it
Worked on both mine and Mrs car, easy to use and navigate menus, gave clear fault codes and the ability to erase, worth it Worked on 2003 pegeot and 2016 focus.
A**.
easy to use with all the great functions all in one unit fantastic bit of kit
very nice unit with both OBD and bat tery tester, ive tried it on my range rover evoque, tho it had no problems,,,,,,ive tried it on my dads citroen c4 picasso as its been to garage they dont know what the fault is,,, so ive pluged in and used this to check the new battery wich has a fault and a obd code due to low prressure add blu,,,,, as im not a mechanic, im a electrician, we can take it to another garage and show them the print offs ive done from the topdon tester via laptop wich is brilliant to look back on,,,,, this is a lovely tester with built in codes you can read about the fault,,, comes in nice case there is a 3.5mm socket on the main lead you canthe functions plug in a 12v supply to power up the unit if you are checking through results and not pluged into car or laptop, this is very good,,,,,,,ive just got to lean all
S**.
Easy to use
Great price and functions range, doesn't do everything but does a lot. Can be purchased without the battery tester but the tester is very good indeed. I have an old fashioned 'Drop tester' which is great but this (battery test function) is streets ahead. Reviews on YouTube too.
E**X
Do it yourself!
When my old Mondeo started to throw up warning messages I enquired at the local garage about finding out what was wrong. They suggested that I take it in and they would put an analyser on it to find out the fault. The bad news was that they wanted £75 to do that - not to repair it, but just to put the analyser on it. I looked around and found that this TopDon analyser comes with good reviews from car enthusiasts. For less than £50 here on Amazon I could have my own. The nice feature with this unit is that it not only gives the fault code, but it also suggests what the fault might be. Once you find where the socket is on your car (they all have one), its so easy to use. The OBD2 connection is universal so you can't go wrong. Well worth the money and recommended for anyone who likes to do it themselves.
S**N
Not as described in product reviews
TOPDON ArtiLink500B While researching this product before purchasing it, the Youtube reviews I watched identified the following as a couple of the more impressive features: (1) LED built-into the OBD2 connector to help locate the OBD2 socket in the car (2) Separate 'Battery Test' cable that is apparently "about 5ft long" so you can attach the lead to the battery and sit inside your car with the reader while testing (3) Lifetime Firmware updates that contain updated vehicle data What you actually get in the box: (1) Cheap looking OBD2 Cable with no LED lamp in it (approx.1m long) (2) A very short cable with 2 crocodile clips on it that plugs into the cable above (approx. 30cm long). So no more than 1.3 - 1.5m in total; that's not long enough to extend outside the engine compartment, let alone allow the unit to be used within the car cockpit. (3) Once the PC utility is installed and the latest Firmware update uploaded to the unit, I realized the last release was V1.03 (released on 25th October 2022). Not exactly what I would describe as an 'active' update program, in fact I wouldn't be surprised if that is the only update this unit will ever receive. As far as using the device is concerned, once I managed to fumble around under the cockpit of the car (without promised LED lamp) and after connecting to the OBD2 connector, the unit did function as a basic code reader. When I tried to test the battery, I then noticed the ridiculously short cable (instead of the generously provided cable in the videos) and I started to wonder how I would be able to follow the various activities such as revving the engine and pressing ok button etc. when the unit is resting under the bonnet and I'm in the cockpit of the car - something the reviewers didn't have any issues with because they had a nice long cable attached. Eventually, I just decided to try the basic 'Battery Test'. I have to mention, the car I was testing was a Mazda6 2.2 Turbo Diesel 2016 with Start / Stop technology that had absolutely nothing wrong with the Battery. The first hurdle I came across was I had to specify what technology my Battery used. Not being an expert on batteries and after consulting the TopDon User Manual, I concluded that the only 2 battery types that are used for Stop / Start are "EFB" or "AGM". As my Mazda battery did not indicate any of the expected types (but did specify a CCA value of 782A), I decided to first try each type: "AGM Spiral" - result: "Replace Battery" "AGM Flat Plate" - result "Replace Battery" "EFB" - result: "Replace Battery" "Regular Flooded" - result "Good Battery" (CCA cannot be specified absolutely, so you just have to pick from a list of 'popular' values, that of course my battery wasn't one of them) So the expected types of battery all resulted in a rather expensive diagnosis. This device is aimed at the DIY sector, surely some lookup data for the various vehicle types or even a mapping between battery label information and the technology used could have been provided? Without this information, how is the DIY user supposed to know what to enter? Conclusion. Disappointed as the manufacturer has obviously provided 'different' specification devices to the reviewers than what's sold to the public. How can the 2 main key features everyone has been raving about be missing in the package? Regarding lifetime Firmware updates; this to me is a gimmick and of no use if the latest version is 2 years old. Finally, the Battery test feature was useless to me as I was unable to determine what battery type I actually had, so couldn't trust any of the results. I shall be requesting a refund though Amazon for this purchase.
T**I
OBD2 Reader
VERY good quality reader,even though its suitable for all cars including European, Japanese & English, Renault was not on the list when checked the menu, so was unable to test the car...pretty disappointing 😑
B**S
An essential piece of kit for every car owner
I’m not a mechanic, and I usually panic if any messages show up on my XC90. I’d trawl the car to the garage and pay at least £75 for the privilege too, just to be told that I’d need a fuse replaced or to top up on coolant (the fault messages aren’t that obvious on the Volvo!) I bought this on a whim because I was having light troubles, and it arrived quite quickly. I was able to find the plug in port and the instructions were very easy to follow. Turns out, I have a defective relay for my rear lights. It was extremely easy to identify once I’d got the scanner plugged in. It will still cost me a fortune to fix, but at least I know what I’m dealing with! I really liked the option on the scanner to be able to view the emissions system of my Volvo as the MOT is coming up and I’m always scared of it failing on that. My favourite feature is being able to clear the codes. I have been trying to clear off the messages about my lights for months, and now I’ve been able to take it off and stop the distractions while driving. I’ve also booked my car in to sort out the relay switch, so it’s been really good and saved a couple of quid! I can also update the software if I need to check the other half’s car too, there’s always a newer car coming into the house. This is a portable device to keep in your glovebox, with a handy LED to help me locate the OBD slot - it’s fiddly, but I can see what I’m doing. My brother wants to borrow mine, but I think I might get him one for his birthday if he’s lucky. I don’t want to get rid of mine.
V**.
Funziona! Ho resettato gli errori della mia Meriva a 1.3 Multijet 55kw 75cv
M**M
Works exactly as expected, showed and cleared fault codes on my 2018 Fiat Ducato. Nice interface and nice colour screen.
P**K
Je possédais auparavant un lecteur OBD Bluetooth et quelquefois je me retrouvais souvent bloqué sur certains véhicules avec impossibilité de lire des codes défauts J’ai acheté le Topdon sur les conseils d’un ami qui l’utilise déjà. Livré dans une pochette de transport pratique et épaisse, cela respire la qualité de fabrication Le menu est paramétrable en langue française A la première utilisation j’ai adoré la led intégrée au connecteur obd permettant un éclairage pour trouver la prise sur le véhicule dans la pénombre du garage Pour l’instant j’ai pu lire les codes erreurs et les effacer sur plusieurs marques françaises, allemandes et asiatiques. Visiblement rien ne lui résiste Affichage des données des capteurs en temps réel avec possibilité affichage sur un graphique pour pouvoir identifier le capteur défectueux Le testeur de batterie intégré à l’appareil est utilisable en changeant uniquement le cordon et permet de voir la santé de la batterie en pourcentage. C’est vraiment super pratique à l’entrée de l’hiver pour savoir si la batterie fera défaut un matin au démarrage. Je conseille de débrancher la borne positive pour faire le test Je recommande vivement ce produit 2 en 1 !
M**.
Talmente semplice che non serve nemmeno leggere il libretto di istruzioni. Le scritte sul display sono in italiano. E' possibile eseguire vari test e resettare le spie delle anomalie (molto utile sulle Citroen con motorizzazioni BlueHDI che hanno problemi di anomalie di urea).
N**S
Ottimo per vedere la diagnosi della spia motore. L’ho utilizzato anche per fare un test accurato della batteria prima e dopo averla ricaricata.
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