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.
Hello. Today, the check engine light on my 2011 E350 Bluetec came on. I used OBD scanner to read the code and I got the attached list of codes. Most of them said: "Test failed since last DTC clear." I cleared the codes and the check engine light went out. What does this test failed mean? Is it any concerning? Will they come back on?
Hello. Today, the check engine light on my 2011 E350 Bluetec came on. I used OBD scanner to read the code and I got the attached list of codes. Most of them said: "Test failed since last DTC clear." I cleared the codes and the check engine light went out. What does this test failed mean? Is it any concerning? Will they come back on?
Thanks in advance.
many monitoring tests have no yet been completed since last clear....
This one is already confirmed.
Wait couple more days for ECU self-tests to be completed. A good deal of codes will come back because something's got your engine upset... glow mgt?
Last edited by CaliBenzDriver; Apr 20, 2026 at 12:58 AM.
Mercedes Teases Updated EQS With Steer-By-Wire and a Yoke
Slideshow: The 2027 update adds a fully digital steering system, revised styling, and potential charging upgrades as the company looks to revive interest in the luxury EV.
Slideshow: From problematic air suspensions to early dual-clutch transmission issues, these specific models and years stand out as the least dependable modern Mercedes vehicles.
