[anamenottaken]

I have a 1997 Vitara and I've been having some engine troubles. I thought I'd try to get some codes from the check engine light, but all I get from it is one single flash when the key is turned. The light is never on when the car is running. See Youtube video for detail. Is this normal? It is the only light on the dash that is on for such a short time when the key is turned.

https://youtu.be/BwsmybGcPw4

[Eddy]

I have a 94 which runs the check engine light full time. small patch of masking tape hides it well ... .

yeah ... I know ... no help whatso-ever

Pretty sure it is linked to the sensor thingy in the exhaust manifold. I have extractors, the fitting for the sensor broke off, so I don't worry about it anymore.
Try disconnecting it ... It may not prove anything, but will give you a sense of whether or not it's linked to anything else as well.

[fordem]

@anamenottaken - I believe the light should come on when the ignition is switched on, and stay on until the engine is started, at which time it should go out if there are no failure codes stored.

@Eddy - it doesn't quite work that way - the ECU does a system check when the ignition is switched on, and will turn the check light on if it detects any "abnormal" conditions, so, in a sense, it is linked to a dozen or more (it varies with the vehicle and it's options) "sensor thingys", disconnecting any one should make the light stay on after startup, but it would prove no more than the light is working - and just so you're aware of it, active codes can be read using nothing more than a paperclip, and the check engine light.

[anamenottaken]

fordem wrote:

@anamenottaken - I believe the light should come on when the ignition is switched on, and stay on until the engine is started, at which time it should go out if there are no failure codes stored.

@Eddy - it doesn't quite work that way - the ECU does a system check when the ignition is switched on, and will turn the check light on if it detects any "abnormal" conditions, so, in a sense, it is linked to a dozen or more (it varies with the vehicle and it's options) "sensor thingys", disconnecting any one should make the light stay on after startup, but it would prove no more than the light is working - and just so you're aware of it, active codes can be read using nothing more than a paperclip, and the check engine light.

Ok. If it should stay on until started I assume something isn't right. Do you know where the check engine relay is located? I tried to find it the other day but had trouble sorting through the rats nest of cables.

[rexhunta]

You need to "trick" the ecu to show the codes.

[Eddy]

fordem wrote:

@Eddy - it doesn't quite work that way - the ECU does a system check when the ignition is switched on, and will turn the check light on if it detects any "abnormal" conditions, so,.

OK ... so I got it arse-about-face then .... pretty much parr for the course when it comes to electronics ....

[fordem]

anamenottaken wrote:

Do you know where the check engine relay is located?

What is a check engine relay? If you're looking for what controls the check engine light - it's wired directly to the ECU, no relays involved - as far as I'm aware, on a 97 Vitara with EFI, there are two relays in the EFI system - the main relay (controls power to the entire fuel injection system), and the fuel pump relay (turns the fuel pump on/off) - there are two more relays under the dash, for lighting control.

[anamenottaken]

rexhunta wrote:

You need to "trick" the ecu to show the codes.

Ahh great. Thank you. I will try this and see if it works.

[anamenottaken]

fordem wrote:

anamenottaken wrote:

Do you know where the check engine relay is located?

What is a check engine relay? If you're looking for what controls the check engine light - it's wired directly to the ECU, no relays involved - as far as I'm aware, on a 97 Vitara with EFI, there are two relays in the EFI system - the main relay (controls power to the entire fuel injection system), and the fuel pump relay (turns the fuel pump on/off) - there are two more relays under the dash, for lighting control.

I can hear relay a click at the exact moment the light goes off in the video. I assumed there must be a relay for the light. I guess it must be something else

[Gwagensteve]

It’s the fuel pump relay turning off after it primes the fuel system.