P0400 EGR Malfunction
11-14-2017, 11:21 AM
#1
Member
Thread Starter
P0400 EGR Malfunction
Just wondering if anyone experience this problem and what resolved it.
This light comes on about 30 miles after reset. Each and every time. Which makes me wonder if it's even EGR. So far I did the following diagnosis:\
- checked all the EGR vacuum hoses
- Checked vacuum/EGR movements (it holds vacuum and moves correctly)
- Removed and cleaned the Intake/EGR pipe (it was actually pretty clean)
- Removed and cleaned the EGR
- Tested the Solenoid while the engine was off (it clicks) HOWEVER when I run the engine and give it power, engine doesn't misfire/shut down.
This is weird, it should if the Solenoid is working.
This makes me think that the vacuum is not even reaching the EGR Valve/Solenoid.
TIA
This light comes on about 30 miles after reset. Each and every time. Which makes me wonder if it's even EGR. So far I did the following diagnosis:\
- checked all the EGR vacuum hoses
- Checked vacuum/EGR movements (it holds vacuum and moves correctly)
- Removed and cleaned the Intake/EGR pipe (it was actually pretty clean)
- Removed and cleaned the EGR
- Tested the Solenoid while the engine was off (it clicks) HOWEVER when I run the engine and give it power, engine doesn't misfire/shut down.
This is weird, it should if the Solenoid is working.
This makes me think that the vacuum is not even reaching the EGR Valve/Solenoid.
TIA
Last edited by S430AMG; 11-14-2017 at 03:28 PM.
11-24-2017, 05:09 PM
#2
Member
Thread Starter
I checked the OHM reading on the solenoid and it went up to 32ohms but didn't stay there, went down right away and jumped around.
I decided to go ahead and replace it, which fixed the issue. I also noticed the idle improved, I had a little studer before.
I decided to go ahead and replace it, which fixed the issue. I also noticed the idle improved, I had a little studer before.
