Thread: EGR
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Old 09-17-2012, 05:49 PM
oab_au oab_au is offline
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Re: EGR

Quote:
Originally Posted by Lookin4SVX View Post
Could you explain to me how the EGR sensors tells the ECU something is wrong?
I figured it was a matter of ohms on the line, like most other sensors.
So I was thinking just replace the line from the sensor with a hot wire of how ever many ohms is the normal reading.

There is no sarcasm in that question. I honestly want to know why it is not possible.
The EGR solenoid is operated by a duty cycle signal. The ECU will detect an open or shorted wiring, and a armature that is not responding to the ECUs signal (stuck or jammed.).

Quote:
Originally Posted by 1986nate View Post
You've got that backwards, a 92 ECU can go into a 92 Cali/94+federal car without a problem. It will never look for the temp sensor. If you put a 92 cali or 94+federal ECU into a Federal 92 car, it will throw a code because there is no EGR temp sensor or wiring. IIRC, the 92 Cali/94+Fed ECU's only need to see the temp sensor is plugged in and existent. It doesn't actually readily monitor the temps. (This may be different for OBD2 versions)
The EGR temp sensor is mounted on the passage that carries the exhaust gas from the exhaust manifold to the inlet manifold. When the ECU signals that the EGR opens, it looks for the rise in temp at that sensor, that confirms that gas is passing to the inlet.
The problem is when the passages in the EGR pipe, and the inlet manifold passages, get blocked with carbon, no gas passes, no rise in temp, gives a code.
So to fix the 56 problem, fit a new solenoid. To fix the 34 problem, clean all the inlet manifold passages of carbon.

Harvey.
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