How Do I Scan For Codes Without A Code Reader?

[Stinger]

[84mustang]

So does the voltage pulse?

[Stinger]

No, the check engine light flashes.

[84mustang]

So is this koeo or koer? And what is the purpose of the meter?

[Strangeleak]

This is for both tests. One of them delivers codes when they key is turned on. The other delivers codes when the engine is on. The ECU will rev the engine to about 3000 for 30 seconds or so then idle down and begin flashing codes. The analog meter is used to see the "flashes". You can also watch the check engine light for codes.

[84mustang]

OK so the meter will pulse? And I'm guessing that its for vehicles like mine without a light

[Stinger]

Yes, the meter will pulse. You need an analog gauge though, not a digital gauge.

[rustybuttrusty]

Is there a way to clear memory codes without a reader? I have a reader coming in the mail but I have no patience.

[Stinger]

I think disconnecting the battery for 30 minutes will clear the "active" codes.

[rustybuttrusty]

Thanks a bunch. Can you explain CM (continuous? memory)?

[Stinger]

It's just historical error codes from the past.

[stocker]

what if the car has no plug? my sons car has no diagnostic plug any chance you could tell me what pins they are? thanks

[Stinger]

It's got one if it's a factory EFI car and it's got a stock harness unless someone removed it (not likely). Pins depend on the application.

[stocker]

no this harness was made by someone, it has only the pins that were necessary for the car to run! it was in a pinto or so i was told when i acquired it in a parts package deal!  ill have to dig up some schematics and trace them down!  thanks