Check Engine Light

[gnappi]

My GF has a Toyota the would lock up the ignition (every time) trying to start it after she hit the parking space bumper on her last park. The "mechanic" told her it's a problem with Corollas and told her to not hit the bumper in the parking lot.

The cause was the remote control battery power was strong enough to unlock the doors but not to disarm the security system. I replaced the battery in the remote nearly 2 years ago and it never happened again.

 

[BillPlayfoot]

Two weeks ago I had that same error code 0440 on my 2003 Trailblazer.
Replaced - fuel tank
- fuel pump/sending unit
- purge valve
- fuel lines
- fuel filter
- gas cap
- air filter
That problem solved.
Now the transmission down shifts and up shifts when driving at a constant speed. Speed up or slow down the transmission is fine. Thinking maybe the transmission solenoids are failing
If I had not just bought this Trailblazer in November I would have junked it.
I have to learn that I cannot afford to buy cheap priced vehicles.

 

[KMixson]

Update, My car still throws this code as I pass through that location. It is going on two years now. I guess I will have to live with it. I only pass through there once a week at the most so it is not too bad. Other than that the car is in excellent shape. It only has 85,000 miles on it. I have taken it on vacations and driven it a thousand miles and no code. As I mentioned in an earlier post I had it tested and they found no problem with the EVAP system. I am thinking it may be electrical interference from something there.

 

[New River Rat]

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August 2017:

I've read this thread and would almost bet that there is some form of electrical interference

February 2019:

I am thinking it may be electrical interference from something there.

Makes perfect sense to me. :wink:

 

[drewestin]

I need a program for my car service, I heard it is very convenient, is it true?

 

[MichAllen]

This is convenient because it allows you to keep warehouse records, calculate the cost of repair/restoration work, generate and issue invoices, acts, work orders, invoices, and other primary and secondary documents. The program autoleap.com contains a module that produces various analytical forecasts and calculations; in addition, the program is equipped with the most powerful reporting system for operations, actions, and documents performed in it. Reports can be generated for any date, any period.

 

[KMixson]

UPDATE! I have found the problem. It is the magnetic traffic light sensor mounted in the roadway on that lane. I was talking to an ASE Master Tech and he told me that could be the issue. I have been testing it over the last month. There are two southbound lanes and two northbound lanes and a center turn lane on the roadway there. As I am going to work at 3:00AM I am usually driving in the right lane across that sensor at that intersection due to no traffic on the road and the check engine light would come on every time. The past few weeks I have driven in the left lane as I went through there and the check engine light did not come on. This morning I was in the right lane and the check engine light came on like clockwork.

 

[LDUBS]

I remember this thread and that it was a real head-scratcher. Thanks for the update!

 

[MrGiggles]

The traffic sensor theory seems like a stretch to me.

I'd say it's more likely to me that specific point in your commute just happens to be when the conditions are met for the PCM to run the evap monitor.

P0440 is pretty simple, when conditions are right (fuel has to be at a certain level, vehicle has to have sat for a certain period of time so the fuel tank has equalized in pressure and temperature), the PCM will run the EVAP monitor, by closing the vent valve and opening the purge valve, which applies engine vacuum to the fuel tank and evap system. It will then close the purge valve and essentially start a timer, while measuring vacuum. If the system won't hold X amount of vacuum for X seconds, a P0440 or P0442 will set.

The diagnostic would consist of first verifying the issue with a bidirectional scan tool, and then smoking and pressure/vac testing the system through the test port to find the leak.

 

[KMixson]

MrGiggles, I have had the car checked by two different shops and extensively by myself and they or I could find nothing wrong with the EVAP system. It has been smoke tested. I can drive it a hundred miles or a thousand and the code will not come on unless I drive through that intersection in the right lane. It would be very doubtful that I could "time" it to come on only at that intersection every time. It will not come on if I am in the left lane as I drive through there.

 

[GTS225]

How about in the southbound lanes or turn lane?
Just suggesting a more comprehensive and thourough test.

And I don't discount the magnetic sensor theory. As an industrial maintenance electrician (retired) I saw more than once where magnetic fields messed with DC electrics.

Roger

 

[KMixson]

Yea, as a mechanic I have seen some weird stuff also. I was kind of hoping the car was sniffing the BBQ joint that I passed just before that intersection. It would be nice to have a car that alerts you to a BBQ joint nearby. BTW, here is the last video I took of the light coming on in that intersection.

 

[MrGiggles]

Yea, as a mechanic I have seen some weird stuff also. I was kind of hoping the car was sniffing the BBQ joint that I passed just before that intersection. It would be nice to have a car that alerts you to a BBQ joint nearby. BTW, here is the last video I took of the light coming on in that intersection.

Hmm. It would be really interesting to graph the fuel tank pressure sensor with a scope while you drive through that intersection. Even just the PID for it in the datastream on your scanner may be enougHh to find any anomalies.

 

[Stand Up]

 

[KristineTate]

The Check Engine Light (CEL) is a warning indicator on a vehicle's dashboard designed to alert the driver to any problem with the engine or emissions system. When the light is on, it means that the vehicle's computer has detected a fault in one or more of the systems it monitors and has saved the corresponding diagnostic fault code (DTC).

 

[KMixson]

I have included a picture from Google Maps on where the traffic light sensor is that sets off the code. It is highlighted in yellow. This is the only place that the CEL will come on. If I am in the left lane, it will not come on.