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HI Guys,
I got a CEL this last weekend... checked with a scanner and got P1529 L/C atmospheric balance air control valve fault.
No change in performance... car has 50K and I've owned it since new. Rarely beaten on.
Any thoughts would be appreciated.
2018 E63S wagon.
The P1529 error code, indicating an “atmospheric balance air control valve fault,” typically relates to the secondary air injection (SAI) system, which helps reduce emissions by injecting fresh air into the exhaust to burn off excess fuel. Though the performance isn’t affected, here’s what might be going on and some steps to take:
Possible Causes:
1. Air Control Valve Malfunction: The control valve that manages the air flow could be sticking or clogged.
2. Vacuum Leak: Sometimes, a vacuum leak or hose issue can cause an imbalance in the SAI system, triggering this code.
3. Faulty Sensors: The code could result from a sensor issue, like the manifold pressure sensor, giving inaccurate readings.
4. Carbon Buildup: Over time, carbon buildup in the SAI ports or valve can interfere with its operation.
Recommended Actions:
1. Inspect the SAI Valve: Check for any clogging or buildup, especially if your vehicle hasn’t had a carbon cleaning yet.
2. Inspect Vacuum Hoses: Look for any loose, cracked, or disconnected hoses around the SAI valve and intake manifold.
3. Reset the Code: If everything looks clean and intact, try clearing the code to see if it reappears. Sometimes minor issues or brief misreadings trigger a code that doesn’t return.
If you’re not noticing performance issues and the code doesn’t reappear after clearing, it could have been a one-off error. However, if it persists, it may be worth having a mechanic with Mercedes expertise take a closer look. Given your car’s mileage, these parts could need cleaning or minor maintenance rather than replacement.
Last edited by PeterUbers; Oct 28, 2024 at 09:23 PM.
as a follow up.. I reached out to MB to make sure that I could drive the car into service with the "P1529" code.
Here is the response:From what I researched, it seems to be related to the secondary air injection system, which is utilized to lower emissions. If there are no drivability abnormalities (no misfires or shaking), I would be comfortable stating that it is safe to drive it to your nearest or preferred dealer.
So I promptly cleared the code, added two cans of Liquid Moly fuel injection cleaner and drove from NYC to the hills of PA ... all in about 500 miles. No new CEL (will check for codes when I get back to my code reader). I did have a "check filler cap" message (the second one I have had ever in any of my benzes...). So that was kinda strange as the first one was on the same day that the CEL came on but not this time.
Your code could entirely be just a gas cap issue vs a much less likely deeper issue with the fueling filling system; you hadn't mentioned the gas cap item in your first post.
Last edited by PeterUbers; Nov 3, 2024 at 03:35 PM.
Your code could entirely be just a gas cap issue vs a much less likely deeper issue with the fueling filling system; you hadn't mentioned the gas cap item in your first post.
That is interesting as my car has always had the ticking noise behind the driver's side headlight. As far as the gas cap... I know for a fact that it was put on properly (kinda hard to screw that up with these caps)... So I thought that warning was more a result rather than instigating. Trust me, I immediately checked the cap and it was on properly.
Considering that you are the only person to respond it must not be that common an issue. (or more likely these days people don't fiddle with their cars as much to try to solve problems)
That is interesting as my car has always had the ticking noise behind the driver's side headlight. As far as the gas cap... I know for a fact that it was put on properly (kinda hard to screw that up with these caps)... So I thought that warning was more a result rather than instigating. Trust me, I immediately checked the cap and it was on properly.
Considering that you are the only person to respond it must not be that common an issue. (or more likely these days people don't fiddle with their cars as much to try to solve problems)
yours is the first report of P1529 and I added this to the sticky; thanks for your circle back to add to the knowledge base
just an update. I drove the car and on the second tank of gas at around the 1/2 tank full I got a warning (as I was on the interstate) about the fuel cap not on properly. It blinked a couple of times and then the CEL came back on. argh...... continued to my house and refilled the car, cleared the code and then the car idled rough and was misfiring and threw the code. Shut it off and restarted and it continued to misfire and or idle rough. Turned if off again and cleared the code.. restarted and it appeared to go back to normal. Drove the car back to the house and parked it. I am going to order a new gas cap and go from there.. will update you guys when I get the car out again as its parked at my beach house for the next two weeks or so.
just an update. I drove the car and on the second tank of gas at around the 1/2 tank full I got a warning (as I was on the interstate) about the fuel cap not on properly. It blinked a couple of times and then the CEL came back on. argh...... continued to my house and refilled the car, cleared the code and then the car idled rough and was misfiring and threw the code. Shut it off and restarted and it continued to misfire and or idle rough. Turned if off again and cleared the code.. restarted and it appeared to go back to normal. Drove the car back to the house and parked it. I am going to order a new gas cap and go from there.. will update you guys when I get the car out again as its parked at my beach house for the next two weeks or so.
you may have the purge issue and need a dealer trip
you can smear some Vaseline on the seal of the current cap and see if it seals any evap leak - if it doesn't you have other issues
Last edited by PeterUbers; Nov 5, 2024 at 09:02 AM.
what is the purge issue? It seems for sure that both times before the CEL I got the gas cap warning...... just the misfire was different this time around.
what is the purge issue? It seems for sure that both times before the CEL I got the gas cap warning...... just the misfire was different this time around.
hey there. I got a 2018 e63s as well, picked it up not to long ago. My car also has thrown this code P1529 and I’m wondering if you fixed or found out what was wrong with the car?
I should mention I am not getting any gas cap messages
Yes I did..It was these two things (sorry to not remember the names and I don't have the receipt in front of me) they are super cheap and you can change them yourself. You can get a cheap OBD reader that will cancel the code and you will be fine. Mine came from NAPA
the problem stems from over filling the tank causing back pressure than over time destroys the seals.
Yes I did..It was these two things (sorry to not remember the names and I don't have the receipt in front of me) they are super cheap and you can change them yourself. You can get a cheap OBD reader that will cancel the code and you will be fine. Mine came from NAPA
the problem stems from over filling the tank causing back pressure than over time destroys the seals.
I believe those are the purge valves that you have circled. Mine have also been ticking like CRAZY, glad to know it’s not anything serious, I am going to get these changed out and will update
FWIW, in case anyone else ends up here, I just had this code when I started the car directly after fueling up. Only filled the tank about 3/4 full though. I started it, it ran super rough, code came on. Read the code and ended up in this thread. Since clearing code an hour ago it's ran fine. Kind of weird since I didn't over fill. Maybe I didn't tighten the gas cap properly. If the problem persists i night order a new gas cap and replace those parts shown above. Mine have been ticking for 4 years, but I hear even new ones do.
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