Reset check engine light

C

conedodger

New member
I had a check engine light which was accompanied by pretty obvious ignition issues, miss on acceleration etc. I bought a used coil pack ($35) and did a trial and error replacement (it was the number 1 so I got it right the first time). Engine is running fine but the dealer wants $110 to reset the check engine light. Any easier way? You used to be able to disconnect the battery for a couple hours.
 
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still can disconnect the battery to reset it. if its still on when you reconnect the battery, then you have some other problems, or the battery hasn't been disconnected long enough. worse case you'll have to stop by an auto zone or something and see if they can loan you the code reader... although i thought CA law put a stop to that for some reason.
 
Disconnecting the Battery is one way to clear the DTC's as Stick Figure mentioned, however an easier way is to open up your fuse box behind your battery and remove the EFI fuse for 1 min. That will clear the codes. (Unless it's a hard code)
 
$110 to reset the CEL? Wow. Please give us the name of that dealership so the whole of our 4runner community can make sure to never go there! Try pulling off the neg. cable for 45 minutes.

Stick Figure,
I heard about that law in CA too about not letting parts stores read codes for you anymore, but I think it's been repealed. I say that because I saw a sign in the window of Autozone saying something like "get your codes read for free" just last week. Either that or it's an old sign.
 
10 or 15 minutes is good, but watch out they may be able to tell if it was reset if you are going to emmisions. The fuse did nothing for me, the battery is what does it.
 
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I don't know how long, but leave the battery disconnected for a while and it will reset. 45min to an hour has always worked for me. If there is still a problem it will come back on, usually no sooner than 50 miles though.

And Brian, I haven't heard that, nor live in Cali anymore, but in Texas to get an inspection they can tell if you disconnected the battery to reset the computer. I had a problem with my cats, and the CEL light was on, but I knew it would pass (long story on how I knew) so I disconnected the battery to turn the light off (you cant pass inspection in Texas with the light on, no matter what!) and went straight to the inspection place. After they hooked it up they asked me if I had had recent work done on the car or replaced the battery, I played dumb and said no. They told me they couldn't inspect it because the computer had recently been reset and for me to drive 50 miles or so and bring it back to have the inspection. From experience the light comes on from 50-100 miles after resetting, but it worked out that I got it inspected after driving the 50 miles, but immediately pulling away after leaving the inspection place the light came back on! haha, oh well it passed! Now I have the URD rear O2 simulator, which keeps the light off, so passing is no big deal now!
 
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The on-board computer reports pass/fail/incomplete for a series of tests. Cat efficiency usually takes the longest, as it requires 2-trip detection and a fairly involved set of test conditions. DMV's will not pass a car that has any tests showing incomplete. (They all go to Incomplete when power is cut to the ECM.) jsmarine had to be lucky enough to complete and pass all tests, hit the DMV, and then have the DTC code thrown and CEL turned on only after he left. I have to assume fault was either intermittent or borderline.

I have a BR-3 scanner and it reports test status readings just as the State computers do. The NJ printout that they give you and the BR-3 screen pass the same test status info.
 
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Pull the battery cables and touch them together to drain the juice out of the computer faster. Just a minute or two is all it takes.
 
if you disconnect battery drain power from vehicle after disconnect by turning on lights and stereo to drain out all power stored. i build tuner cars and do this alot.
 
zacktshields said:
Disconnected the positive battery cable for 30 seconds and worked for me on my 2016 4runner trail edition
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werk71 said:
if you disconnect battery drain power from vehicle after disconnect by turning on lights and stereo to drain out all power stored. i build tuner cars and do this alot.
Click to expand...

In this day and age, there is no excuse for not owning an inexpensive Bluetooth code reader that will do the reset AND give you the code.
 
TheDurk said:
In this day and age, there is no excuse for not owning an inexpensive Bluetooth code reader that will do the reset AND give you the code.
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i use a cheap 375$ one. but just resetting the light doesnt set fuelmaps and spark plug voltage back to stock maps. some times fuel maps and voltage maps get re wrote so many times depending on what you cars health is it needs reset all the way. inexpensive readers dont always have features, some just read and cant write, if you get one make sure it can actually write then you'll be in better shape with this stuff.

<a href="https://ibb.co/X2bsmjS"><img src="https://i.ibb.co/7YXW7j2/IMG-3745-1.jpg" alt="IMG-3745-1" border="0"></a>
 
werk71 said:
i use a cheap 375$ one. but just resetting the light doesnt set fuelmaps and spark plug voltage back to stock maps. some times fuel maps and voltage maps get re wrote so many times depending on what you cars health is it needs reset all the way. inexpensive readers dont always have features, some just read and cant write, if you get one make sure it can actually write then you'll be in better shape with this stuff.
Click to expand...

ALL the Bluetooth adapters will write, assuming you use the Torque Pro app on it, which is the way to go. They will also live scan and do just about anything that fancy one will do, and with a much better screen if you have a tablet. You probably can do much more. Torque is really only limited by what the CAR can do over OBDII; if the PID is there, Torque will display it, graph it, alarm it, or whatever. Cheap wired adapters, whether they write or not, really have no place in the modern world unless you just can't figure out how to use a smartphone app.

Your point about the maps is valid, assuming you DO want to reset those.
 
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Ancel and other basic OBDII reader/clearing devices are super cheap. I got one for $20 and can hand it off to any friend that wants to read and clear codes. It's floating around with whoever needs it. That's the only 'advantage' over the app-driven BT devices - some of those are pretty awesome. Killing all stored data with a power drain seems like overkill and not knowing CEL code the engine is throwing is borderline negligent. I also feel my rig has programmed a nice EFI path and paired with a performance muffler and air filter are good for nearly +2HP :biggrin1:

Amazon.com: Code Readers & Scan Tools - Diagnostic, Test & Measurement Tools: Automotive
 
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