My 2000 Nissan Altima started exhibiting a frustrating problem: it would stall when accelerating. Despite this, the engine would still start after stalling, but the stalling recurred upon acceleration or when under load. The “Service Engine Soon” light was illuminated, prompting me to seek a diagnosis. A friend used his OTC scanner, and after connecting it, the car bizarrely wouldn’t start at all. It would crank, but not turn over. Frustrated, we left it overnight.
The next morning, surprisingly, the car started again. I managed to drive it home and performed some basic maintenance: changing the fuel filter and oil. The car seemed to run okay for a day, but then the stalling issue returned while my daughter was driving. Determined to fix this myself, I began researching online and decided to invest in my own OBD2 scanner from Amazon, opting for an Ancel 410 for $73.00. This decision to get my own scanner car tool proved invaluable.
In the interim while waiting for my scanner car tool to arrive, I explored other potential causes on YouTube. This led me to discover a vacuum hose that had been chewed through – likely by a rodent that had nested in the engine during winter. I had removed a nest earlier, which now seemed like a clue. Replacing this damaged vacuum hose appeared to resolve the stalling issue. The “Service Engine Soon” light remained on, but the car ran smoothly through several test drives. It seemed the vacuum leak was the culprit behind the stalling and the warning light.
Once the car was running again, my friend returned with his OTC OBD scanner to finally read the error codes. Even though my own scanner car tool was still in transit, we were able to retrieve the following codes using his scanner: P0100, P0505, P0325, P1490, P0446, and P0464. However, another unexpected issue arose: connecting the OBD scanner a second time caused the car to refuse to start again, even after it had been running perfectly. The “SES” light also still needed to be addressed.
Back to YouTube for more research! I discovered that scanners can sometimes interfere with the Engine Control Module (ECM), requiring a hard reset. This reset can be performed by disconnecting both battery terminals and then briefly connecting them together for about 10 seconds (ensuring they are disconnected from the battery itself). This process discharges the capacitors in the ECM. Following these steps, I attempted to start the car again, and thankfully, it worked! This ECM reset, triggered by using Scanner Cars, got my Nissan Altima running once more.
