Service Engine Soon LIght "Code P0400" ?????
Thread Starter
Advanced
Joined: Apr 2002
Posts: 79
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From: South Jersey NJ
Service Engine Soon LIght "Code P0400" ?????
Any help would be greatly appreciated.
I have a 96 Camaro Z28 and the Service Engine Soon light came on,
I work at a import car dealer and one of the mechanic used a scan tool and pulled the code P0400 EGR System Malfunctionm, not being a import they are unsure what this could be ( is too rich, too lean etc.)
The forum has always been very helpful when I owned my Corvette so I figured maybe some one might have some helpful information.
Thanks again :seeya
I have a 96 Camaro Z28 and the Service Engine Soon light came on,
I work at a import car dealer and one of the mechanic used a scan tool and pulled the code P0400 EGR System Malfunctionm, not being a import they are unsure what this could be ( is too rich, too lean etc.)
The forum has always been very helpful when I owned my Corvette so I figured maybe some one might have some helpful information.
Thanks again :seeya
Drifting
Joined: Jun 2001
Posts: 1,997
Likes: 1
From: Lake Ozark MO
Re: Service Engine Soon LIght "Code P0400" ????? (Rome856)
My bet goes to a bad EGR solenoid valve (not activating to supply vacuum to the EGR valve) or a bad EGR valve itself.
I had this code intially when I first got my car. A Mity-vac test on the EGR valve showed the diaphram to be bad. Quick replacement and all was good.
You need to see if you're getting a vacuum signal to the EGR valve. If true then check the EGR valve itself.
That should be a good starting point.
I had this code intially when I first got my car. A Mity-vac test on the EGR valve showed the diaphram to be bad. Quick replacement and all was good.
You need to see if you're getting a vacuum signal to the EGR valve. If true then check the EGR valve itself.
That should be a good starting point.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Re: Service Engine Soon LIght "Code P0400" ????? (Rome856)
The quick way to diagnose this - clear the code. then, start the car. If the code comes back immediately, then its the control valve, if it takes a while, its the EGR itself.
you see, the computer will sence a bad control valve during initial self test at startup, but it won't find the EGR until it goes into closed loop...
you see, the computer will sence a bad control valve during initial self test at startup, but it won't find the EGR until it goes into closed loop...
