That "Blank, Blankity, Blank" Check Engine Light!

[RaySendero]

My check engine light is on most the time now!!!

Have had an intermittent problem with my check engine light coming on for 3 months.  Been driving it with no problem.  I've had the error checked several times - Diagnostics say its an Emission Gas Return (EGR) valve malfunction each time.

The ports are clear (not plugged) at the exhaust & the fuel injector system, the EGR valve checks good, and the slave valve checks good.  The vacuum lines are clear, too and they heat up properly when the engine it on.  The problem probably lies in the temperature sensor but could be the main computer.  This sensor is $169 plus installation and tax.  A new computer is $524 plus ins/tax!

  I don't like the idea of continuing to drive with the CEL on as you'll ignore other "important" problem that will also turn the light on!!! 

Does anyone know of a way to fool or short the temperature thermocouple to show heat so the light will go off and any other problem will show?

[R.W.Dale]

it would help if we knew what we were working on.

[RaySendero]

it would help if we knew what we were working on.

I assume its just a basic thermocouple, although I'm not sure how it works.  Does the resistance change as the temperature changes?  If so, would it be possible to wire a resistor across its leads?  At least that way I could determine if it is the temperature probe or the computer.

[torpedoman]

If it is a ford take the e.g.r. valve apart and clean it 10 minute job after the first time. problem is usually a bit of carbon under the valve keeping it from seating properly and turning on the light.

[RaySendero]

If it is a ford take the e.g.r. valve apart and clean it 10 minute job after the first time. problem is usually a bit of carbon under the valve keeping it from seating properly and turning on the light.

torpedoman,

The EGR valve has been cleaned , checked and is fine.  As a matter of fact, the whole system checks out to be working just fine - Just the temperature sensor (or computer) isn't registering any heat when the exhaust gases pass by the sensor.

[kevthebassman]

I went through this check engine light BS before.  Missouri now makes it so you cannot pass an emissions test if your check engine light on.  Most every car over 50k miles has it's check engine light on!  I put $500 in my car to try and get it to pass, still no luck.  My mechanic pretty much ran out of things to fix that weren't more expensive to fix than the car was worth! 

In the end, I ended up unplugging the battery to reset the sensor a half a block away from the garage.  I passed the emissions test with flying colors.

[Beers]

I know with certain makes, the "check engine" light comes on at a certain number of miles (whether there is a problem or not) and will not go off  until you take it to the dealership and plug 'er into the diagnostic computer. If you like to service and maintain your own vehicle, you may just have to deal with the light.

[RaySendero]

I know with certain makes, the "check engine" light comes on at a certain number of miles (whether there is a problem or not) and will not go off  until you take it to the dealership and plug 'er into the diagnostic computer. If you like to service and maintain your own vehicle, you may just have to deal with the light.

Yes, I aware of that.  I've had this error checked and its on due to "ERG valve malfunction".

[RaySendero]

I went through this check engine light BS before.  Missouri now makes it so you cannot pass an emissions test if your check engine light on.  Most every car over 50k miles has it's check engine light on!  I put $500 in my car to try and get it to pass, still no luck.  My mechanic pretty much ran out of things to fix that weren't more expensive to fix than the car was worth! 

In the end, I ended up unplugging the battery to reset the sensor a half a block away from the garage.  I passed the emissions test with flying colors.

    Thanks

[kevthebassman]

When the system screws you, screw the system.

[Paladin]

Ford? Differential pressure feedback egr sensor, not a thermocouple. go to ford and get one and put it on yourself, not difficult 2 rubber hoses, one electrical connection and 2 10mm nuts. If ya go to a parts store there is a 50/50 chance it will be wrong.  good luck

[Jack Ryan]

  I don't like the idea of continuing to drive with the CEL on as you'll ignore other "important" problem that will also turn the light on!!! 

Put a piece of tape over it and don't worry about it.