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Discussion Starter #1
I have an 89 MX6..turbo.i pulled codes from the computer but have no idea what they are

I pulled codes

4 and 16

The check engine light illuminates all the time when the car is started....It runs ok..but slightly on the rich side.

Any help would be much appreciated

Thanks
Anthony
 

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How did you read the codes? I know mine comes on cause the EGR clogs up. Am I supposed to reset it after i clean out the valve?
 
G

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Discussion Starter #4
There is a single wire with a green plug on the end of it...it sits on the drivers side...almost on top of the strut tower.

To pull codes you will need to ground this wire.....plug a piece of wire into the plug and the other side to ground.
Turn the key to the run positon and the ecu will display a series of flashes on the check engine light window. Count the flashes to match the code or codes being displayed.

For example: If the light display 4 flashes in rapid sucession then it would be a code 4. There is a momentary pause of the light if more than one code is in memory.

As for the egr...a number of things can cause an egr code to be displayed. check the following:


1. the egr can get coked with carbon causing it to stick in either the open or closed positon causing the positon sensor to display one reference voltage all the time. This will set a code. For example: The ecu will use a reference of five volts. The sensor is a potentiometer meaning as the valave is closed you will get a reading of 1.00 volt.....when the valve is full open you will get a five volt raeding. This is how the ecu knows what the egr valve is doing. If the ecu is getting a 2.00 volt reading all the time...it knows something is not ight and sets a code.
2. the vacuum line connected to the egr valve could be loose, clogged, or cracked causing the egr not to move in any position.....replace vacuum tubing if it shows evidence of fatigue.
3. Im not sure if this engine has one yet but usually the egr will be controlled by a n electically controlled vacuum solenoid. If this solenoid is shorted, or has open open winding, the egr will not operate properly. It is possible to have an intermittant problem with this as well.
4. the egr vacuum diaphragm is broken or ruptured. This is a simple test....just connect a vacuum pump and see if it holds and moves. It is possible to have a good diaphargm where it will hold vacuum and move the valve but if the itake is coked with carbon you can still have other driveability problems.


Hope this helps

Anthony
 

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Thanks, that helps a lot, but should I reset the code or not, and how?
 
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Discussion Starter #6
Yes you should reset the code. To reset your ecu do the following:

1. Disconnect negative battery cable

2. hold down brake pedal and turn the headlight switch to the on position. The reason for doing this is to ensure the ecu will not hold a memory once you reconnect the battery cable. By doing this, you will drain the "stored" energy in the ecu's capacitors, electronics, etc.

3. Reconnect negative battery cable.

If the code is a hard fault code(meaning the problem is still present) the engine light will come back.

If the code is a soft fault code(meaning it happened, you resolved the problem) all stored codes will be lost by resetting the computer.

Anthony
 

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FYI Nostromo, the EGR valve does use a solenoid.
 
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