A couple of days ago, I had to take Cary’s Volvo in for repairs. The air conditioning had stopped blowing cool air, and with the spring coming up, I knew that fixing the air conditioning was something we wouldn’t want to wait on. I was prepaired to wait a little longer to fix it, but last week, the “check engine” light warned of another problem, so I decided to bite the bullet and have the A/C fixed while the shop diagnosed the CE light.
The A/C was an easy fix — a bad relay needed replacing — but the Check Engine light was another issue. It seemed as though the Atmospheric Pressure Sensor was malfunctioning. While that sensor probably wasn’t really necessary in Raleigh — it helps the engine adjust fuel pressure to compensate for a lower- or higher-than normal atmospheric pressure, such as when driving in the mountains — I really didn’t want the CE light staring at me whenever I drove the car, so I dropped it off at the Volvo dealership and walked to work.
A few hours and a few hundred dollars later, the dealership called me to let me know the car is ready. A friend dropped me off at the dealership after 5:00pm, and I paid and picked up the car. But as soon as I started the car, the Check Engine light glowed menacingly at me.
I pulled back up to the repair bay — hadn’t left the parking lot yet — and let them know that the light was still on. I figured they probably just forgot to reset the computer. So one of the techs plugged the car into the diagnostic computer and tried to reset the light, but it wouldn’t clear. He then said that the light was actually on because of another malfunction. The computer was now saying I had a bad air intake temperature sensor.
I asked the manager who was with us, “Isn’t the timing of that a little odd?” The manager responded, “Well, things break when they break. Can you bring it back in tomorrow?” The Volvo people are always really nice, but his response was a little odd. Wasn’t it possible that they had made a mistake and accidentally messed something up?
Not wanting to wait around any longer, and knowing that this particular problem wasn’t going to cause my car to explode, I decided to drive home and bring the car back in the next day.
When I got home, I thought I’d open the hood and just take a look. I’m not a grease monkey, but I can identify a lot of the innards of most cars. I can change the oil — but as compact and cramped most car engines are these days, I choose not to — and I know just enough about engines to be dangerous, but I wasn’t sure exactly what the sensors looked like. I popped the hood, and it didn’t take me long to spot the new atmospheric pressure sensor. It was the only really shiny, clean piece of plastic visible on the top of the engine, a small dark green box about the size of a large grape, connecting two cables.
As I was looking at the new sensor, I spotted another sensor closer to the front of the engine. It was about half the size of the other one. I realized that the part of the sensor I was looking at was just an electrical plug that plugged into the side of the air intake near the grill. Logic told me that must be the Air Intake Temperature sensor, and it was unplugged.
I kicked myself for not asking the guys at the dealership to pop the hood and check. They were apologetic about the issue when I returned the car the next morning, and now the mean Check Engine light is, for now, vanquished.

« »