Question about ECU Scanning

[artpogi]

I just want to have some clarification.

Although my CEL (check engine light) have not turned on yet, I was thinking of having my ECU scanned because of some weird behaviour of my engine while running.

My questions are:

1. can the ECU scanner (MUT) find/read/detect an error/problem if the CEL is not on?

2. can it only detect errors if the CEL is on? If so, I guess there's no point having the ECU scanned if the CEL is not on, tama ba?

Thanks very much.

[4JGtootsie]

Sir Art.

Sometimes you can use a jump wire to retrieve trouble codes but there is a procedure which depends on your car manufacturer, year and model. Flashcodes in certain interval and lenght gives you the diagnostic trouble code.

[artpogi]

Sir Art.

Sometimes you can use a jump wire to retrieve trouble codes but there is a procedure which depends on your car manufacturer, year and model. Flashcodes in certain interval and lenght gives you the diagnostic trouble code.

Sir 4JGT,

okay, thanks very much for the info.

[torque2006]

there are ways to tap into your ECU, as 4JG said, but you'd have to be confident with what you're doing.

different brands of vehicles have different ports to tap into the ECU. casas have their own ECU scanners. as for service centers, they use universal ECU scanners which can be updated yearly.

the scanner's objective is to retrieve the error codes, if there are any. it is primarily for diagnosis. it will be easier for the mechanic to isolate the problem.

when a trouble code is retrieved, the technician looks at what code was sent out (for obd1 you have to look at how many flashes the MIL displayes then find a match on the code book, for obd2 the scanner displays the error code on the screen.) the technician then tries to clear the code. if the code doesn't clear up, then a sensor might be malfunctioning. if the sensor is ok, then a part of your vehicle might need repairs/replacement.

usually, the MIL (malfunction indicator lamps) turns on, like check engine light, ABS, etc.

but there are certain times when there are no MILs don't turn on but there's a problem with a sensor. i had that experience with a particular nissan cefiro before. the engine was just running rough. apparently one of the o2 sensors is busted.


boss art, your vehicle is a mitsu lancer right? you can try having your ECU scanned, if you think yours has a problem . mura lang naman pag japanese car ang pinapa-scan.

na-try ko na sa lancer ko, ok naman walang trouble-code

[artpogi]

torque!

thanks very much for the explanation.

I already had in mind what you and 4JGT said, but I just want to make sure.

yes my ride is a 97 Lancer GLXi, di ko gusto takbo ng oto ngayon, alam ko mga sakit/sira ng oto ko, but this time mukhang may iba eh, feel ko lang ika nga, that's why I'm thinking of having my ECU scanned.

Since it's not that expensive naman 500 - 700 yata depende kung saan, okay na din, at least for peace of mind ipa scan ko na.

thanks again guys