C43 Runs Great But This Issue Is Has Me Beat
Thread Starter
MBWorld Fanatic!
Joined: Feb 2010
Posts: 1,506
Likes: 130
From: Bolingbrook Illinois
1999 C43 Amg
C43 Runs Great But This Issue Is Has Me Beat
I have 6 codes that suppose to be making the engine light turn on.
4 are O2 sensors and one the purge valve in the engine and the other fuel canister vent valve.
All 6 parts got replaced, the vent valve was replaced months ago.
I have no power going to the purge n vent valve which is located under the driver side back wheel. I have checked all the fuses and all are good. I checked the relays as well and replaced the ones I couldn't check.
Is it possible the ecu not working as it should? Besides the check engine light the car runs great with awesome power. Only issue is I can't put gas like normal. Gas nozzle keeps popping as if the fuel tank is full which is not. I know it could be because the purge n vent valve is not working. ...
Any ideas why or how I can fix/check why I'm not getting power to the valves?
4 are O2 sensors and one the purge valve in the engine and the other fuel canister vent valve.
All 6 parts got replaced, the vent valve was replaced months ago.
I have no power going to the purge n vent valve which is located under the driver side back wheel. I have checked all the fuses and all are good. I checked the relays as well and replaced the ones I couldn't check.
Is it possible the ecu not working as it should? Besides the check engine light the car runs great with awesome power. Only issue is I can't put gas like normal. Gas nozzle keeps popping as if the fuel tank is full which is not. I know it could be because the purge n vent valve is not working. ...
Any ideas why or how I can fix/check why I'm not getting power to the valves?
MBWorld Fanatic!
Joined: Mar 2005
Posts: 2,418
Likes: 194
From: America
1999 C43 AMG, 2005 E55 Wagon
You said all 6 parts were already replaced.
Were they replaced because of this same issue?
If you already had the trouble codes and the check engine light on, then replaced all those parts, it could very well be that no one cleared out the codes after the repairs.
I imagine a large number of trouble codes, once triggered, will cause the ECU to stop utilizing the parts it thinks are broken. Try clearing the codes/resetting the ECU and see if the codes come back.
Were they replaced because of this same issue?
If you already had the trouble codes and the check engine light on, then replaced all those parts, it could very well be that no one cleared out the codes after the repairs.
I imagine a large number of trouble codes, once triggered, will cause the ECU to stop utilizing the parts it thinks are broken. Try clearing the codes/resetting the ECU and see if the codes come back.
Thread Starter
MBWorld Fanatic!
Joined: Feb 2010
Posts: 1,506
Likes: 130
From: Bolingbrook Illinois
1999 C43 Amg
Thanks. Yes the wiring was checked at all points I could find.
And I did have a mechanic cleat the codes. Is clearing the codes the same as resetting the ecu?
If no how do I reset the ecu? I have already disconnect the battery for 10-15 minutes. The check engine does go off but comes back with same error codes. Even when the mechanic cleared all the codes the light and the same error codes came up.
Thanks in advance for the help.
And I did have a mechanic cleat the codes. Is clearing the codes the same as resetting the ecu?
If no how do I reset the ecu? I have already disconnect the battery for 10-15 minutes. The check engine does go off but comes back with same error codes. Even when the mechanic cleared all the codes the light and the same error codes came up.
Thanks in advance for the help.
Super Member
Joined: Dec 2009
Posts: 940
Likes: 0
From: Chapel Hill, NC/Montreal, QC
1995 C36 AMG, 1998 C43 AMG
Thanks. Yes the wiring was checked at all points I could find.
And I did have a mechanic cleat the codes. Is clearing the codes the same as resetting the ecu?
If no how do I reset the ecu? I have already disconnect the battery for 10-15 minutes. The check engine does go off but comes back with same error codes. Even when the mechanic cleared all the codes the light and the same error codes came up.
Thanks in advance for the help.
And I did have a mechanic cleat the codes. Is clearing the codes the same as resetting the ecu?
If no how do I reset the ecu? I have already disconnect the battery for 10-15 minutes. The check engine does go off but comes back with same error codes. Even when the mechanic cleared all the codes the light and the same error codes came up.
Thanks in advance for the help.
Thread Starter
MBWorld Fanatic!
Joined: Feb 2010
Posts: 1,506
Likes: 130
From: Bolingbrook Illinois
1999 C43 Amg
He used some small thing like autozone uses to pull codes. But better much better tool. ..
Shouldn't there be power on the wires of the valves when is on and running?
Before I would turn the ignition on and I could here the canister vent valve click. Now I don't here it. And for the purge valve it would start ticking away after a few minutes the car is on.
These valves now only work when direct power is on them.
Shouldn't there be power on the wires of the valves when is on and running?
Before I would turn the ignition on and I could here the canister vent valve click. Now I don't here it. And for the purge valve it would start ticking away after a few minutes the car is on.
These valves now only work when direct power is on them.
Trending Topics
Thread Starter
MBWorld Fanatic!
Joined: Feb 2010
Posts: 1,506
Likes: 130
From: Bolingbrook Illinois
1999 C43 Amg
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Junior Member
Joined: Nov 2012
Posts: 55
Likes: 0
1998 C43 w/ N/A 5.4l swap
you either have a blown fuse or a burnt contacts on a internal relay of your k40 relay module. the module sits on the passenger side of the engine compartment were the diagnostic connector is. remove the 4 screws and the cover and you will see the relay module its approx 10 dollars for this part. it is simple plug and play. this forsure supplies the power to the charcoal canister shutoff valve and also the purge valve. it also supplies the power for all 4 02 sensors. replace this and your car will be fixed
MBWorld Fanatic!
Joined: Mar 2005
Posts: 2,418
Likes: 194
From: America
1999 C43 AMG, 2005 E55 Wagon
you either have a blown fuse or a burnt contacts on a internal relay of your k40 relay module. the module sits on the passenger side of the engine compartment were the diagnostic connector is. remove the 4 screws and the cover and you will see the relay module its approx 10 dollars for this part. it is simple plug and play. this forsure supplies the power to the charcoal canister shutoff valve and also the purge valve. it also supplies the power for all 4 02 sensors. replace this and your car will be fixed
Thread Starter
MBWorld Fanatic!
Joined: Feb 2010
Posts: 1,506
Likes: 130
From: Bolingbrook Illinois
1999 C43 Amg
Thread Starter
MBWorld Fanatic!
Joined: Feb 2010
Posts: 1,506
Likes: 130
From: Bolingbrook Illinois
1999 C43 Amg
MBWorld Fanatic!
Joined: Aug 2006
Posts: 7,053
Likes: 398
From: A.D., U.A.E
2000 (W202 C200) & 2000 (W202 C55)
Besides, If you have a bad K40 switch, check the all "7" fuses & the main black relay first, before ordering the unit....!!
ZAYED,,
Junior Member
Joined: Nov 2012
Posts: 55
Likes: 0
1998 C43 w/ N/A 5.4l swap
I have 6 codes that suppose to be making the engine light turn on.
4 are O2 sensors and one the purge valve in the engine and the other fuel canister vent valve.
All 6 parts got replaced, the vent valve was replaced months ago.
I have no power going to the purge n vent valve which is located under the driver side back wheel. I have checked all the fuses and all are good. I checked the relays as well and replaced the ones I couldn't check.
Is it possible the ecu not working as it should? Besides the check engine light the car runs great with awesome power. Only issue is I can't put gas like normal. Gas nozzle keeps popping as if the fuel tank is full which is not. I know it could be because the purge n vent valve is not working. ...
Any ideas why or how I can fix/check why I'm not getting power to the valves?
4 are O2 sensors and one the purge valve in the engine and the other fuel canister vent valve.
All 6 parts got replaced, the vent valve was replaced months ago.
I have no power going to the purge n vent valve which is located under the driver side back wheel. I have checked all the fuses and all are good. I checked the relays as well and replaced the ones I couldn't check.
Is it possible the ecu not working as it should? Besides the check engine light the car runs great with awesome power. Only issue is I can't put gas like normal. Gas nozzle keeps popping as if the fuel tank is full which is not. I know it could be because the purge n vent valve is not working. ...
Any ideas why or how I can fix/check why I'm not getting power to the valves?
Thread Starter
MBWorld Fanatic!
Joined: Feb 2010
Posts: 1,506
Likes: 130
From: Bolingbrook Illinois
1999 C43 Amg
Thanks for all the replies! I took off the cover from the ecu 5-6 screws.
I did not know there were fuses there. I found one that was bad, replaced it and now the check engine light is no longer on. I hope it stays that way. Thanks everyone!
On another note, my car has the xenon bulbs.
I was told it was a D2R that I need to buy. But, I want brighter lights as it is hard to see when roads are really dark. Can you guy suggest which bulbs to buy that are brighter than the ones that came with the car?
I did not know there were fuses there. I found one that was bad, replaced it and now the check engine light is no longer on. I hope it stays that way. Thanks everyone!
On another note, my car has the xenon bulbs.
I was told it was a D2R that I need to buy. But, I want brighter lights as it is hard to see when roads are really dark. Can you guy suggest which bulbs to buy that are brighter than the ones that came with the car?
Last edited by speed43; Aug 27, 2013 at 09:10 PM.
