When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
The CEL came on for thermostat, coolant sensor, ambient sensor, and cylinder 6 and 2 misfire also other random misfires. I replaced all of the above along with new spark plugs and still CEL won’t go away. Ambient sensor reads the temperature fine now and I already ran it more than 100 miles. The car does run better now with new coils and spark plugs just can’t figure out why the light won’t go off.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Do you have a scanner?
A scanner is absolutely the first "accessory" you want to get. Otherwise, you'll never really know what problems lurk unless you take it to a shop and you'll pay more to have the shop scan the car for you. Check Amazon for:
iCarsoft MB V3.0 (not MB II)
Launch Creader Elite Benz
Foxwell NT510 Elite
BlueDriver
BlueDriver is the least expensive and a pretty good scanner if you just want to know what codes are there and to clear them. Beyond that, you'll want one of the others. They all will automatically identify your car and scan for codes, and give you the option to clear them. The top 3 will allow you to do other things if you ever start tinkering, such as changing your brakes, resetting maintenance counter, etc. Even if you don't do your own maintenance, it's good to know what is going on. You have a complex vehicle and need to know when something important is wrong or not.
If the check engine light is on there is either an active code or still a stored code. Scan it again and see what codes show up. Then erase all the codes and see what if any codes come back. Something could have happened during the repair work, loose connection, didn't put something back properly etc.
Who originally scanned the car to get the codes to know what to repair? Did you do the repairs or take it somewhere? If you took it somewhere id assume they would have cleared the codes and made sure everything is fixed before handing it back over. or its a brand new code.
If the check engine light is on there is either an active code or still a stored code. Scan it again and see what codes show up. Then erase all the codes and see what if any codes come back. Something could have happened during the repair work, loose connection, didn't put something back properly etc.
Who originally scanned the car to get the codes to know what to repair? Did you do the repairs or take it somewhere? If you took it somewhere id assume they would have cleared the codes and made sure everything is fixed before handing it back over. or its a brand new code.
I worked on it myself and made sure everything was connected properly. I also went to get it scanned and it reads the same codes the air ambient sensor went away when I changed it the first time but then it came back. The sensor is working fine though It reads the temperature on the dash. I’ll try buying a scanner and erasing the codes I had an employee at Oreillys try it with his scanner and it showed it wasn’t able to erase dtc code
A scanner comes in very handy. I started with just an inexpensive one and I was able to diagnose and fix my Mercedes and my fathers Chevy truck with it. Both turned out being faulty purge valves which was a crazy coincidence. From my limited experience these inexpensive ones seem to only read and erase codes that trigger a check engine light. Since then I got a better scanner with Mercedes specific software, it is able to tell me a lot more with the car. The first time I hooked it up it came up a bunch of codes that the inexpensive scanner never showed. I gave the inexpensive one to my father just so he has something to read codes if his check engine light ever pops on he can read and tell me what codes it says instead of having to wait for me.
If you dont have the money for a higher priced scanner right now I can recommend the Konnwei KW310, ive used it so know it works. And its one of the least expensive scanners I can find, under $15.
I worked on it myself and made sure everything was connected properly.
I also went to get it scanned and it reads the same codes the air ambient sensor went away when I changed it the first time but then it came back.
The sensor is working fine though It reads the temperature on the dash.
I’ll try buying a scanner and erasing the codes I had an employee at Oreillys try it with his scanner and it showed it wasn’t able to erase dtc code
I couldn't agree more with previous posts: you'll save money by buying yourself a scanner.
Launch Creader Elite Benz
These cars have over 50 networked modules interacting. When something goes wrong, fault codes get registered for technicians.
Once you are able to scan your car, we'll be able to prioritize what needs fixing. These cars have many ways to misfire.... such as:
Bad Ignition: plugs, boot, coils
Low fuel pressure: pumps, filters
Lean mixtures: O2/Lambda sensors
timing components defective
Bad Voltage: alternator output low
If you keep up with maintenance then failures are no surprise.
Coolant and brakes both require simple periodical flushing to prevent extensive repairs.
Enjoy,
Last edited by CaliBenzDriver; 10-23-2023 at 12:45 PM.
10-19-2023, 09:46 PM
