Happened to be pulling up to get my oil changed when the alert came flashing on the screen. The oil change folks did mention that I had no coolant although I have been 100% on top of my services at the Nissan dealership. Unsure how that could even be. After paying $175 for the full monty and flush etc. The message flashed yet again. They did a code reach of P0404.

According to Google "What Does the P0404 Code Mean? Diagnostic Trouble Code (DTC) P0404 stands for Exhaust Gas Recirculation Circuit Range/Performance Problem. It is a generic OBD trouble code that activates if the powertrain control module (PCM) detects erratic Exhaust Gas Recirculation (EGR) valve performance."

I will be calling Nissan on Monday since they are closed tomorrow (Sunday) to try to get some feedback and will update the post.

On 1/21/24 at 48,605 Miles my 2020 Nissan Altima 2.5 SV had this warning message with various lights come on "Engine Malfunction Power reduced Service now" while I was very away from home.

I was driving for around 30 minutes, and I was looking for a place to park when the message came up. The vehicle at that same moment, did something weird. The car kind of... vibrated on and off every second or so. It was similar to when you are turning your car on or off - that same motion. The vehicle did not let me accelerate which was frightening. Almost like being in accessory-mode, but I was in drive. Thankfully I was in the parking lot, but I cannot imagine this happening on the highway.

I do not know why the other lights came on as well. I checked my oil (which Nissan had changed two weeks prior) and my fuel cap to make sure that was tight, and my oil was fine. Both were good.

The reason I have not marked this as solved because this was so recent, and I have been continually dealing with it. I don't know if it is fixed, but Nissan had some proposed solutions and suspects they may have fixed it.

First, they said I should try to replace my battery. It was cold outside (40-ish degrees, which is not very cold if you ask me) so they said the weather could have impacted my battery. Which was funny considering it was testing in the mid-green. I just did it anyway because the episode scared me so much. Cost was about $207 at Walmart for the same battery I already had, but the dealership quoted me $380. Then a couple weeks later, the same (or similar) thing occurred again. It did not display the same message, but rather the weird power reduction occurred with the vibrations or on/off and the warning lights came back up. It is possible that I accidentally made the warning message disappear by pressing something on my steering wheel, who knows.

Then, another week later and I am once again far from home, and it happens. I go to the nearest dealership and my car tested for codes. This is what the paperwork from the dealership states: "ECM reprogram, cause of CEL ECM program is behind cause p0101 code to stay" and also "recalibrate decel G-sensor calibration cause of ABS light." The cost for this was around $340 because my particular extended warranty does not cover recalibration, only replacement (I have spent a small fortune recalibrating sensors in this car).

The dealership seems to think all of these issues combined have somehow contributed to the engine malfunction light. What they have explained it to me as, is that "the sensors were acting up which made the car think something was wrong, when nothing was actually going wrong with it." I don't know if I believe that answer, but that is what they said.

Since then, the problem has not occurred however it has only been about 14 days.