22
You've come to the right place. There's a lot that you can do on your own. Even if all you end up doing is gathering more information for the mechanic who ends up working on the car, they never mind a hint as to where the problems might be!
What are some of the possible causes for the "check engine" light that
can be diagnosed at home?
All of them. ...
16
It could be that you are cornering so hard that you're pushing the oil in the sump to one side, away from the pickup pipe. This temporarily means you're oil pump is sucking up air and you are starving your engine of oil.
Competition cars are equipped with with baffled sumps or dry sump systems to prevent this happening. In a standard road car, this type ...
14
A Set of Standards for Error Codes
I'm sure that someone is going to come up with a much more exhaustive answer, but for a good start, you need to understand that there are MANY different standards for reporting vehicle diagnostics.
For example, take a look at the OBD II Pids Article on Wikipedia. Think of your car's computer as only as powerful as the ...
10
A P2757 DTC is a torque converter clutch solenoid valve issue
The valve engages a torque converter at higher speeds to lock your transmission and engine at a 1:1 ratio. This engagement, obviously, only happens at higher speeds for fuel saving.
Causes include;
Dirty transmission fluid
Faulty line pressure solenoid valve SLU
Line pressure solenoid valve ...
7
Does it make the most sense to replace an old car's entire exhaust system all at once?
Considering your car is almost 10 years old, having to replace all of the parts in the exhaust system does not sound unreasonable, especially if your locality uses any type of road solvent during the winter months (they didn't in Montana where I'm from originally, but ...
7
This is normal behavior - When the engine is not running, there is no oil pressure, so when the ignition is turned on, that light will be on. As Larry says, this functions as a bulb test so that you know that it is working. When you start the engine, the oil is pumped round, the pressure goes up and the light goes out.
7
How do I pull error codes from my Kawasaki motorcycle?
Here are the instructions to pull error codes from your 2001 or later Kawasaki street motorcycle.
Step 1
Pull off your seat and near the battery negative terminal there will be a self diagnosis lead coming out of a connector. The wire is yellow. It looks like this.
Step 2
Get a wire, one with ...
7
I think you may have mistaken a service interval indicator for a check engine light. Modern cars will ask to be serviced at regular intervals, even if no fault exists. There indicators can usually be reset the but procedure is usually manufacturer specific. A check engine light is something else and generally indicates that a fault has been logged by the ECU....
7
The fact that you can smell fuel in the exhaust is a strong indication that the engine is running rich.
This means that there is more fuel than required by the engine. There are many things which could cause this and the sensible course of action would involve hooking the engine computer to a scan tool to retrieve data about fuel trims, and O2 sensor health....
7
That's the check engine light, or CEL - if it lights up, you have a problem with the engine and should stop and investigate it.
If it's blinking, count the number of flashes, as this will indicate a particular error code which can help you to determine what is wrong.
6
The Engine System Service Required is a service interval indicator. The engine check light coming on will mean you have a fault.
You can simply re-set the Engine System Service Required by carrying out a simply re-set. Button A is located at the bottom and to the left of your speedo.
Ensure all doors are closed, Turn the ignition key to position 1(...
6
I was able to find the exact verbiage on Amazon for a Toyota gas cap. It implies that you will get a CEL (check engine light) and you could, which could cost you money to get it checked out.
Here is the listing:
Genuine Toyota (77300-33070) Fuel Tank Cap Assembly
by Toyota
Genuine OEM Toyota Gas Cap New in Original Packaging with Seal.
The typical ...
6
Maybe its a stylised 1950's era air-filter pancake on a carburettor throat?
source
Icons tend to be retained long after the thing they were based on has changed substantially
5
This should not cause you an issue, but this sounds more like a problem with the O2 sensors than with the intake gaskets. When was the last time you had them changed? If you are over 100k miles without new ones, I'd highly suggest this first.
One way to check your theory for the intake gasket is by using a spray bottle with water (on jet, not spray). With ...
5
Camshaft position sensors are usually Hall sensors, which translate changes in magnetic field to changes in voltage.
As far as proximity is concerned, this should be taken care of by the shape and design of the sensor more than the correct tightening torque. By appropriately torqueing down the sensor you are ensuring that it doesn't get loose during ...
5
Turns out this particular issue wasn't due to me running the car out of battery (I believe) but actually to a blown fuse. I guess I had previously left the OBD II plugged in for awhile and apparently if anything else "on that circuit" is turned on it can blow the fuse, and my kids may have turned something on and voila, fuse blown. Another effect of having ...
5
Because it's dangerous with erroneous data
This is actually very smart on Subaru's part. I have to give them credit.
If you have sensors that are faulting you could be giving an ECE false or eroneous information. The ECU would then take that false data and make adjustments to traction control and engine power. You could be on a wet or icy surface, step ...
5
The P1506 code is an idle air control overspeed error.
From autocodes.com:
The P1506 code means that the engine idle is out of factory specification. Sometimes the Idle Air Control (IAC) may have carbon built up. Disconnect the car battery, remove the valve, clean, re-install valve, and drive the vehicle for about 5 minutes with the headlights and A/C ON to ...
5
If you're worried about the car passing emissions testing, seeing the check engine light go off is a good sign. Where I live, you can't be failed because the light used to be on.
The status of the code (often showing up as a check engine light) depends on the computer in the car. Obviously, if the light is on, the code is active. Quite often, though, the ...
4
With some variation based on model year and country of use most faults will latch and self clear. By latching the fault, it is stored and in some cases the "check engine light" also referred to as the MIL (malfunction indicator light) will remain lit after repair until certain conditions are met. The conditions for the fault to clear may involve a certain ...
4
The Air/Fuel Ratio (A/F) sensor 1 is installed in the exhaust system and detects oxygen content in the exhaust gas. The A/F sensor transmits output voltage to the Engine Control Module (ECM). A heater for the sensor element is embedded in the A/F sensor (sensor 1). If the A/F sensor (sensor 1) voltage is low, the air/fuel ratio is lean, and the ECM uses A/F ...
4
Basically this is a bulb test. The CEL and Oil pressure light stay on until the engine is cranked. Air bag lights, ABS lights as well as others flash a certain number of times or stay on for a few seconds then turn off. This is normal operation for those lights.
answered Apr 10 '14 at 21:29
Move More Comments Link To Top
18.7k4 gold badges50 silver badges76 bronze badges
4
The OBD2 code P0442 means that on your system you have a small air/vacuum leak. Apart from the seal on the gas gap, you must check the purge valve and the fuel tank pressure sensor are both working correctly. EVAP faults can be be notoriously difficult faults to pinpoint as the system only checks itself when the vehicle is actually operating and the ...
4
The diagnostic systems in cars get upgraded every few years. It wasn't until the early 2000's that car manufacturers really started to integrate ways of displaying diagnostic info without an OBD scanner.
Typically if it is not included in the shop manual it is not a feature on that car. Your best bet is to go to the local autoparts store or shop and have ...
4
It sounds to me like you mechanic friends are correct. From your description, the car was driven too long on low oil and is now suffering the effects. If you have topped the oil off and are still having the knocking sounds, it's more than likely the engine has damaged bearings with a classic rod knock to tell you about it. With a rod knock, it is only a ...
4
The check engine light comes on for issues that the ECU can detect from its many sensors. The ECU controls fuel and spark. This means the ECU will not come on for mechanical issues that cannot be detected by a sensor. However, some of these items can cause a misfire code.
Some Examples:
Air filter clogged
Exhaust leak
plugged cat
clogged fuel injector
...
4
If the condition that caused it to come on is a minor fault, and stops occurring, then yes, it will clear itself. If the condition indicates a larger problem, then it will stay on until cleared manually.
A good example of a condition that will clear itself, is low brake fluid. I experienced this myself when I would only have the light come on when ...
4
As this article points out, the ability to blink codes was available with older OBD-I vehicles. Once the OBD-II standard hit, the ability to "blink" out codes was lost. This changeover to ODB-II happened in 1996 for vehicles sold in the US.
I know the same is true for Volkswagen cars. Early models had the ability to blink out the codes when something was ...
4
Those symptoms could well be caused by an air leak allowing unmetered air into the engine. This would cause a weak mixture when driving which could explain the lack of power and the cutting out. It would also explain the revving when stopped because idle is primarily controlled by limiting the air intake into the engine.
Check all the air pipes, including ...
4
There are scanners that will talk to OBD1 computers, but most shops (I would guess) don't have the equipment anymore. I got rid of my OBD1 equipment last year. I've seen ≤ 2 cars that required me to use it in the past 4 years.
Maybe a GM dealer would still have the equipment. You would have to call around and ask.
By jumping pin A to pin B on the ALDL the ...
Only top voted, non community-wiki answers of a minimum length are eligible