Good Morning, my 2004 CLK 320 cab with 109,000 miles showed the check engine light last week. A local independent garage found and cleared what they called an "egr" code but did not replace or repair anything. A few days and very few miles later, the check engine light is on again. Before I take the car back to this garage, should I be concerned about anything specific? Thanks.
Thanks Rodney, the shop pulled two codes: one code was p2001 and the other was p2203. They indicated the p2203 was a transmission code but I haven't had any issues with the tranny. I am scheduled to take the car back to the garage Monday to see what's up. Any suggestions?
The P2203 transmission code indicates an error on the speed sensor, which is fairly common. The fix is to replace the conductor plate, which on the 722.6 is not terribly expensive. It requires no coding so it's just a pan-drop and some bolts and electrical connector to deal with.
The P2001 is often a problem with the vacuum transducer for the EGR valve. Either it's bad or the vacuum hose is broken. It's located on the right (USA passengers) side of the back of the engine.
Hi Rodney, I took my car back to the garage this morning and they re-checked and again found the P2001 egr code. The mechanic "probed" the electrical connection, which activated the egr valve, causing the engine to run poorly. He said this indicated the valve was working properly and indicated there was not a vacuum leak. He suggested that I drive the car for a while and, if the light comes on again, it might be due to carbon buildup in the passageway in the manifold. He indicated this could be cleaned out which should improve the functioning of the valve. Does this sound reasonable? He seemed to know what he was talking about but it was way over my head. Any advice? Dave
For P2001, SDS simply says to check the vacuum control of and the transducer itself. It says nothing about a clogged valve. It leads me to believe that the P2001 is a symptom of the valve not being able to activate as opposed to the valve not working.
I think you are looking at OBDII codes "P2001" - this is DTC P2001 (OBDII P0400). Going through SDS's diagnostic process and choosing this DTC, the response is "Check component Y31/1 EGR Vacuum transducer"
I think you are looking at OBDII codes "P2001" - this is DTC P2001 (OBDII P0400). Going through SDS's diagnostic process and choosing this DTC, the response is "Check component Y31/1 EGR Vacuum transducer"
Thanks for the input Keyhole and, Rodney, I don't know about clogged valves or anything but I watched the mechanic ground a probe and insert it into the electrical connector at the valve. The test light came on and the engine idle became significantly rougher. He told me that that meant the valve was activating correctly and letting exhaust gases into the intake manifold. Please excuse an uninformed question but is the transducer separate from the valve itself and could the valve be operating correctly but not the transducer? If so, what might I tell this mechanic to possibly steer him in another direction? Thanks to both of you. Dave
The transducer is a round metal thing that looks like a flying saucer. It will have a vacuum hose connected to it. It's basically a diaphragm that activates the valve when a vacuum is pulled.
Thanks for clearing that up Rodney but back to the original question: if grounding the electrical connection causes the egr valve to activate, does that mean the transducer is operating correctly or could it still be defective?
Rodney, I hope you can clear up a question I still have regarding this egr situation. After reviewing the relevant pages from the WIS, it looks like the vacuum transducer (Y31/1) is separate from the vacuum reservoir (89/2). Since the P2001 error code refers specifically to the transducer, would it be possible to replace just the transducer and not the whole egr valve? Is this part even available separately and would there be enough cost savings to justify this action? My garage quoted me $250.00 for the egr valve alone without labor.
The technician inserted the test probe into the electrical connector at the front of the transducer (Y31/1) and activated the egr valve but I don't know if this indicates the transducer is working correctly or whether he bypassed the transducer in doing this test. Any advice will be greatly appreciated. Thank you, kwikdave.
I've never had an EGR problem, but surely it is vacuum operated - not electrical. Any electrical connection would be for sensing the diaphragm movement for diagnostic reasons.
There's heaps of information on Google advising on how to clean an EGR valve, including Youtube videos. It looks very straightforward in the WIS procedure, but access up at the bulkhead is very limited, so this could make life difficult.
So your fault could be:
a) pneumatic. damaged hose.
b) mechanical. EGR valve blocked with soot. Faulty vacuum transducer. I think there is a spring inside.
c) electrical. bad sensor - mis-reporting a fault.
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