Diagnose your car troubles with this top-rated scanner

Originally published at: https://boingboing.net/2019/05/05/diagnose-your-car-troubles-wit.html

But not the codes which are manufacturers’ proprietary information, I think.


Glancing at the headline I read it as top rated Scammer. Probably pretty close the first time.

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All these devices are based on the reference implementation published in the magazine Elektor years ago. Check for ELM327. Documentation can be found under www.obddiag.net

The adapters exist in several versions and can be cheaper than this offer. They do work, but are limited to standard OBD2 features and most manufacturers use extended or different protocols for the really interesting parts. But this device will still give you invaluable info about your car engine.

Iphone users need one working with wifi. Android users can use bluetooth and may want to install fdroid to get a really open source app. The app will tell you the numerical error codes, then it is Our job to type those into google, adding the brand of your car.

Just imagine the face your garage mechanic will make when you bring the car in and tell him “the relay for the heating plug is toasted, error code xxx.xxx”…


The big question for me is, will it read Prius-specific error codes? The one ELM327 unit I tried so far – which promised to do just that – doesn’t.

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For android, I used torque from the play store, the pro version https://play.google.com/store/apps/details?id=org.prowl.torque is very nice in terms of resetting errors and creating a dashboard. $4.95 and it will look up error codes so you don’t have to. there is a free version: https://play.google.com/store/apps/details?id=org.prowl.torquefree

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You’re correct. Proprietary codes need manufacturer specific reader.

I have one of these and it works great for generic Pxxxx trouble codes and for resetting Check Engine lights. You can also leave it plugged in all the time for real time performance diagnostics while driving too. Just be sure it turns off with your car or it can drain your battery.

I use Engine Link app for iPhone and I hear Torque is the best for Android.

I can tell you though that just knowing the code, while helpful, is not the whole picture. Interpreting trouble codes is part art and part sorcery. Just knowing that code P0237 is a knock sensor doesn’t really help. You really need to understand what the different codes mean in relation to each other to pinpoint the root cause of an issue.

Most of the time you’ll get many codes at the same time like knock sensor low voltage AND cylinder 3 misfire AND O2 sensor open circuit AND intake throttle body error. You gotta look at the whole picture and know what causes what to figure out that it’s due to a bad spark plug for example.


Of course. One will not be able to use the codes without having some knowledge of the engine details. I just wanted to say that mechanics are less ans less used to customers knowing what is under the bonnet, that is all.



And this too. My struggle every day is fighting to get others to understand this, and explaining why it’s not just a simple look-up table. I tend to troubleshoot systems that go “whoosh”, and “swoosh”, and go to places where pulling to the side of the road isn’t an option.

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I have a cheap one, Fixm MS3000, that reads them. Reads and resets the battery problem codes, which are pretty prius specific. Gen II Prius.

Most cars have a funky no-tools way getting the error code when that stupid Check Engine light goes on.

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Thank you! That’s exactly the sort of thing that has me searching for one (3rd gen, but that shouldn’t make a huge difference, far as I can tell). Intermittent HV system isolation faults. Which can be “OMG, your main battery is shorting onto the body of the vehicle!” or “yeah, we got some condensation on the wiring, and there’s a micro-fracture in the insulation that tripped the alert.”

Since I’m not dead, I’m pretty confident it’s the latter, but it’s still unnerving as fuck, and I have to take it to my mechanic to clear the code every time, since my reader won’t even see the error state.

This is the closest I could find to the unit you’d mentioned. If you have a link for the precise unit you have, I’d appreciate it!

This is what I have, but don’t know that there’s anything magical about it, it was the first one I bought. I think I grabbed it as it was a cheap deal on slickdeals.
It might be easier, if your error keeps popping up, to just buy any variety locally that you can return if it’s not scanning and returning codes. You can certainly have issues that don’t throw codes, but my understanding is that if you’re getting the Red Triangle of Death, it will give you some data, though as others have said, not the complete picture. My understanding is limited. Also, for the Gen 2, if you’re getting a battery specific code, very often a fan for the battery in the back seat comes on too. Check on Priuschat, they usually have much more expert advice than me. Good luck.

Hmmm, mine was OK but worked for a whole 3 months before crapping out…

… some deity somewhere has a fucking awesome sense of humour. As I’m heading home this afternoon, the “Hybrid System Error, stop the car in a safe place” message pops up.

Keep in mind, this tends to happen once every six months or so. And of course, I have to drive someone to the airport 90 miles away in two days, so I can’t even get a different scanner in time to try and troubleshoot.

Now, the big dilemma: Do I just ignore the error for two days until my handful of scanners shows up, or do I suck it up and go to the garage to get the error cleared?

It always annoyed me that modern cars have such a wide array of sensors and onboard self-diagnostic gizmos but are purposely built so that the consumer can’t just see the code light up on the dashboard. It should be a built-in feature.

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Torque also has lots of community-built PID files for when you want to get extra-fancy with your vehicle monitoring.

Gotta be careful though, scanning things yourself can be hazardous…

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Really dunno. Might be different error codes outside of normal OBD II, so readers may not give you data. Relevant Priuschat thread:

So, the somewhat bewildering conclusion: I gave my OBD2 scanner another try (Veepeak Mini Bluetooth). It has always been able to connect to the car successfully, but not able to see the High Voltage ECU, so Torque always reported no fault codes even when I was getting the orange triangle of doom.

It still couldn’t detect the fault code – but apparently it could clear the error! And, since the fault is intermittent and I’m mostly worried about the indicator staying on and masking some more serious problem, this largely solves my issue.

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