Mechanics, advise on a code reader

I need a code reader for a car that seems to have gone off the deep end. The battery died and I replaced it. The fuel line came loose (clip popped out) and I fixed that. It ran like a swiss watch for one day and then it went nuts. Started it up and it started to shut things down in an odd way. First the anti-lock brake system shut off, then the radio, then the blower motor, then the dash lights, then the turn signals. This all happened in the space of a half mile. Got it home and parked it for a few days. Started it up and everything worked but it was a Christmas tree of dash lights. I’m afraid to drive it to a parts store to use their code reader.

What am I looking for in a code reader? What features are worth $200 or less.

I borrowed one from my dad last year. I think he said it was one notch up from the cheapest available at Harbor Freight, maybe $60ish? It was really nice, bright display, quality cable, handy case.

The cheapie ones give you a code. That’s it.

The better ones give you a code and also tell you what it means. They are also programmed with specific manufacturer codes that may not be part of the standard set.

Another feature to look for is whether or not it can give you live data while the vehicle is running (engine speed, coolant temp, o2 sensor readings, that sort of thing).

A longer cord is a nice feature.

They also have bluetooth scanners that can pair up with your phone or tablet. I haven’t tried any of these personally so I don’t know how well they work. You are looking for the same basic features, though. Does it give you an explanation of what the code means or does it just give the code, and can it do live data. Cord length isn’t so much of an issue though. :slight_smile:

ETA: Plan on maybe $25 to $30 or so for a cheapie, more like $70 to $100 for a decent one.

Why did your battery go dead?

Battery was old and just shorted out. It had about 9 volts when I checked and wouldn’t take a charge.

I’d do something like this. Generally cheapies just give a code, a few more dollars let’s you clear codes ,which you need, everything more expensive Is mostly niceties until you get up over a grand and start actually being able to program something.
However, it sounds like you’ve got a loose ground connection. Since the battery was just replaced check everything in that area especially. Even more so any ground wires connected to the terminal that aren’t the main one.

Don’t discount the possibility of the main wire hiding a lot of corrosion either. 95 percent of the time if you’ve disturbed something just before a problem occurs the problem is in that area somewhere.

I’d be surprised if a code reader is helpful in this situation. I think Littleman is on the right track – it sounds like an electrical glitch. If so, a code reader will merely reflect this but not shed any light on the actual cause. I agree that it makes sense to carefully check the battery cables and their connections.

that makes sense but it ran great in the rain the day before. You’d think it would have died then. But checking anything that’s been disturbed sounds like a good place to start.

Is there any use to a scanner that records real-time data for replay? Or for that matter just displaying real time data? I’ve always wanted a code reader but didn’t know what was really useful.

Basic code readers are good for retrieving and displaying the error code(s) that caused the Check Engine Light (AKA Malfunction Indicator Lamp or MIL) to illuminate. Generally speaking, those are things that affect the emissions efficiency of the vehicle. Some vehicles set code(s) for transmission issues. Better code readers have features that include a broader array of codes, help interpreting the code, suggesting possible fixes, ability to reset the MIL (will come back on if issues aren’t fixed and you can’t fool an emissions station by simply turning the light off), real time graphs and charts, ability to transfer data to a laptop or tablet, etc. While I’m with Gary T in thinking a code reader will do no good for your current issue, they are handy to have around. I have a Harbor Freight model that I spent about $100 for 8 or 10 years ago. I has all the features I listed above, has performed flawlessly on any vehicle I’ve hooked it to and has saved me a ton of money over the years.

Off topic story - It’s funny how many times I have showed up to look at a private sale used car and been told “Everything runs fine!” only to hear a whole different story when I pull out the code reader and ask if they mind if I hook it up. And how many times the seller thought they could fool the code reader because they removed the bulb or reset the light with their own reader :rolleyes:

Yes, when you get to the 100ish dollar range, many of them have Live Data. Pick the sensors you want to monitor and they’ll display (to the best of their capabilities) what’s going on. For example, you’re having acceleration problems, tell it to display the throttle position sensor, MAF sensor, fuel trim(s) and see if any of them get wonky when you punch the gas.

When you get up over $500ish, then you get bidirectional capabilities. With that, you can tell the car to activate things. For example, you’ve got a code for something evap related. You can trigger various solenoids and listen for them (as well as monitoring pressure in the fuel tank to see if it’s doing what it should be doing.
Window won’t roll down…have the scanner roll it down, if it goes down, you go after the switch as opposed to the motor or one of the modules.

There’s a million things they can do, but yes, many/most of them will display (and record) live data.

For more information than you’d need take a look at youtube channels for EricTheCarGuy or ScottyKilmer or SouthMainAuto or ScannerDanner. They’ve all (maybe not Scotty) talked about scanners at great length at one time or another.

I got this one for half price during a flash deal. It’s been fine so far. It reads and deletes codes and has the descriptions for about half the codes I’ve seen. The ones that it doesn’t are simple to just google. It does live data and I think you can get a snapshot of the live data from the time that a code was generated, but I haven’t actually tried to do that yet.

Do you have a smartphone? I got one of these for $10. Amazon.com

It uses Bluetooth to link up to my Android. You can also download a free app (Torque?) that allows you to check codes, reset emissions monitors, and do real-time data monitoring. For $8 or so, you can get a more advanced version of the same program, or for more money, any of a number of other programs with greater abilities. I generally look up what the codes mean on the internet and work on diagnosis from there.

I’ve used it before on my car; it’s pretty slick. I might use it to start, and if you need more information, move up to a more capable scanner.

A buddy of mine has one of the fancier ones. Its bluetooth and not only does it tell what the code means it gives you, in order, the most likely causes of the code and fixes for them. $100 I think.

The one I have is a bluetooth dongle that fits into the OBD-2 port. With the Torque Pro app installed, it lets me pull the codes and it’ll query a database to tell me a better description for the code itself. No suggestion of what might cause it, but google is usually pretty good for that.

It also lets you do things like log data- you can just turn the app on and drive somewhere, and it’ll log whatever sensors you like- gas flow, water temp, RPM, etc… and in a really cool twist, you can display those overlaid on Google maps- it’ll show like 500 RPM as green, 4000 as red, and everything in between as a color gradient. So you can not only see that your RPMs hit 3250, but you can see where on the map that happened. It’s not necessarily super-helpful in terms of troubleshooting, but it is kind of a cool thing.

Thanks for all your input. Feel free to add more. I’m still going to buy a scanner at some point. The weather improved enough to poke around on the engine as suggested. It’s not charging. 13.5V at idle and it drops way off if the throttle is touched. There’s a bit of a whine when the engine is revved up. Looking like the alternator.

I agree with this post 100%