97 E300 EGR valve
 

I'm continuing to troubleshoot my P0200 engine code on my 97 E300.

I removed the sensor connector to the EGR valve and ohmed the contacts. All three contacts showed open circuit (in any combination). I even removed the sensor part from the EGR valve and actuated the plunger on the sensor, still with no effect on the ohmmeter. I'm assuming the internals to this sensor are just a simple rheostat, but it's sealed so I can't get at it.

Vacuum part of the EGR valve works fine.

Dealer says $719 for a new EGR valve. :eek:

I'm confident that the sensor is bad, but I would like confidence that replacing it will cure my P0200 code.

So, my question is, could someone with a 96 or 97 E300 pop the EGR connector off and reply with the ohm readings across the three contacts? I'd like to substitute resistors in there to identify whether the code goes away at startup.

Thanks

I have the same car that is also throwing P0200. This code can mean several different things, and you really need a manufacturer specifc code reader to get to the details. My subcode is P1975 and it is related to the crossover valves. Car runs great so I haven't been too ambitious about getting it resolved. Here is the thread where I pull my hair out trying to resolve it:

http://www.peachparts.com/shopforum/showthread.php?t=258494

If you read on the page 3 area, you will see some discussion of the EGR.

So, you never fixed your P0200 code? In your post #24 of the above referenced thread, you posted a pic of the egr valve and it's connector (green, red, blue wires). If you remove that connector and measure the resistance across any two of the three contacts on the egr valve, what readings do you get?

Sorry, on vacation for a few weeks and not where the car is. When Iget back would be happy to check if you haven't rec'd an answer yet.

Still haven't solved my P0200 code, but mine is related to the car not thinking the flap is opening when it really is. I think it is a bad wire coming from the flapper switch that gives tells the CPU that the flap is open. Unfortunately, it will probably require another removal of the intake manifold to address the issue, and since I know the flap is working, and since the car is running great, I have not been too motivated to fix it.

Have you checked all vacum lines to the resonance valves in the intake? Those are usually the issue with this code. Also consider pulling the intake and cleaning those flaps (if you havent already) I have a 96 E300 if I get an opportunnity today I will put an ohm meter on the contacts.

I wanted to follow up to close the thread with the solution to my P0200 code.

I had removed crossover pipe and IM and cleaned both flappers, and exercised with my mityvac, and confirmed that the limit switches were functional.

I went to a local indy that claimed he had a Mercedes reader. He came up with both 1475 and 1476 codes which points to the flappers.

With engine running, I confirmed that both flappers were functioning

...frustrating.

I pulled up AllData and identified the contacts on the connector at the computer. Both flappers were receiving 14v at the computer. Removed crossover pipe with all lines still connected and engine running and confirmed that both connections at the switchover valve were receiving zero volts.

Upon messing around with the engine on, I found that touching the harness area actuated the flappers. Identified that the common wire to both flappers had corroded and come loose at the switchover valve, even though it was phyisically still in the correct location.

Repaired the connection, code went away, all is well.