There was one simple trick (Click HERE!) which would reset the light.
It also showed up on the mechanic’s diagnostic as having been tricked.
I heard that 40 miles would probably cause the light to come back on after that trick.
Maybe make sure your test drive is >40 miles? Note the mileage, and tell seller to call you once another 40 miles are on it?
As noted, the light can be ignored in States which do not do emission tests.
It can also be a very bad idea to ignore it.
How to tell the difference?
Find out what is causing the problem - then you can decide if it is important to you.
If you can’t interpret the code (“IAT Sensor” was the one I found). I happened to recognize IAT as Intake Air Temperature - a $10 dollar part and a couple of hours of my time (I installed the new one with quick-connect couplings crimped onto the power leads)
In a Toyota vehicle with the 2.4L 2AZ-FE engine, the light means your consuming oil and you should bring it in to the dealership for the oil consumption test. Then you wait for the possible recall.
Yes, disconnecting the battery will clear codes and the light will be off for a bit, but you’ll fail inspection because the PCM will report “OBD monitors not ready” if scanned. Once you’ve driven enough (a few dozen miles will do it) the monitors will re-engage and put the MIL back on if the fault is still present.
My CEL was O2 sensors failing. And also a air intake flap position sensor (reading to verify the flap is correctly set for warmed, or not warmed, air.)…
I had bought the blue tooth adaptor and installed ODB-I (1998 toyota v6… ) software…
So I could get the codes and these parts were the parts that failed.
It can be that the code is erroneous the problem is something other than what the code says
How about In a Toyota vehicle with the 2.4L 2AZ-FE engine, the light MIGHT mean your consuming oil and you should bring it in to the dealership for the oil consumption test. Then you wait for the possible recall.Bolding my changes.
The light means the computer has detected a problem and will report what it detected with a code. Then, as already described the code may indicate and identify an actual problem, or not. Have fun from that point on. I don’t know if there are statistics available but I’d bet the vast majority of the time the light indicates a real problem has been detected, though it may be nothing more than a gas cap that isn’t fully tightened.
No, it’s a lot more than just distance. Some of the non-continuous monitors need to see drive cycles under a variety of conditions, like stop-and-go, highway driving, acceleration, number of cold starts, etc. The problem will likely recur when one of those monitors reaches the appropriate condition in its testing cycle, which as mentioned may take a few days.
In one case in a previous vehicle, when I turned off an annoying MIL it literally took more than a month before it came back on. That’s unusual, but it happened. I think this was due to what at the time was a very small evap system leak.
We had three Volvos that developed “check engine light” issues with multiple diagnostic code “solutions” coming up–none of which worked for more than a few weeks :mad: There’s a lot to like about Volvos but this was an unfortunate issue that just pushed us away. After 21 straight years of owning Volvos we got rid of the last one and replaced it with . . . a Kia.
This was the killer for us. We’re in a state requiring yearly inspections and a CEL on equals an automatic failure.
A CEL could be anything from tightening the gas cap to $1,000 in repairs. It’s a risk you take.
I myself just recently bought a used car for my daughter (“on behalf of”, actually - she paid) with a CEL. The dealer - who seemed like a nice guy but had one of these fly-by-night operations selling on Craig’s List - told me he thought it was the MAF sensor but couldn’t guarantee it. I/we decided to roll the dice (after negotiating the price down considerably) and it turned out it was indeed the MAF sensor. Which is easy to replace and costs about $125 for a brand name part.
But it could have ended quite differently.
Worth noting that these inexpensive code readers give only the broadest description of the problem, and to pin it down further you need equipment which is not worthwhile for a non-professional to buy.
Personally, I think it might be a good idea to test all potential used car purchases with a code reader if they don’t have a CEL on. Because if the result comes back as “code not set” then that shows that not only is there a possible CEL issue but that the dealer is possibly a crook attempting to hide that. (It’s also possible that he repaired some sort of problem and reset the code thinking it’s cured, but it should lead to heightened caution.)
When I was younger, I remember that there was a CEL light that came on just after X number of miles, and all you had to do was reset it to say that the engine had been checked.
Is this still normal? And does the fact that they are trying to sell it without resetting mean that it must be more than that? Or might it be worth it to try resetting it yourself and seeing what happens?
Somewhere around 30 years ago there were some cars that had a light come on at 60,000 miles, with the specific instruction being to change the oxygen sensor as a preventive maintenance. I don’t remember what the light said. The reset procedure typically involved pushing a little button on the back of the instrument cluster.
My CEL light comes on for any scheduled maintenance item, including regularly every 3000 miles for oil change. It’s a complete hassle, I have a little plug tool to reset the light myself.
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Different states, different ways to deal with the Check Engine Light. Colorado has this strange law:
Effective January 1, 2015, an illuminated “Check Engine” light will cause vehicles eight (8) to 11 model years old to fail emissions. … Although the emissions testing cycle, for vehicles 12 years and older, can be completed and passed, the light can indicate problems with the vehicle.
No clue what happens to a vehicle between new and 8 years, although I believe that new vehicles are exempt for a period of time (but 8 years?).
I don’t know if my 2001 Toyota qualifies as a modern car, but it was an indicator that the evaporative gas recycling unit was failing. Here in Ontario we do have mandatory emissions inspections every second year once the car reaches an age of 7, so it was an issue for me.
Anything since the early '90’s is a modern car. Before roughly 1990, many cars became rust buckets; after, many cars wore out or were totaled before rusting out. That’s also about when manufacturers starting putting more gauges and warning lights on the dashboard. And that same time is when cars starting coming out with knobs that you turn for heating, air conditioning, etc., rather than levers that you slide.
Cars sold in the US after 1/1/1996 are OBD2-compliant; AIUI, cars sold in Canada after 1/1/1998 are OBD2-compliant. This means your check-engine light is required by law to indicate any malfunction that can cause emissions to exceed government-mandated limits. The evaporative emissions control system is one issue, but the other is tailpipe emissions; if the computer sees a problem with misfire/incomplete combustion, or a failed O2 sensor, etc., the light will come on.