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The Yankee Express

Crankshaft position sensor may be culprit in engine failure

John Paul

Q. I have a 2001 Jeep Grand Cherokee. Several months ago, it would not start and the light with the key symbol with the line through it was on and it would not start. Prior to this it would occasionally shut off while I was driving. My mechanic said it was the skim module. I took it in, and he advised me that the PCM was bad. I found the part on eBay, and he installed and programmed it. It ran fine, but then it started randomly shutting off again. I brought it back to my mechanic and he could not find anything wrong. He said to drive it for a little bit to get the PCM to”set.” It was fine for a week, no issue and it began randomly shutting off again when I am driving. When it happens, I just put it in park, turn the ignition to off, and turn it on again, and it starts right back up. I am going to call my mechanic again today. Have you heard of anything like this? Any insight would be appreciated.
A. It sounds like you may have had two problems, the key indicator, certainly could have been the SKIM (Sentry Key Immobilizer Module), and the ECM (main computer) needs to see that signal for the car to start. I would have the technician look at the crankshaft sensor as well as checking for codes. The crankshaft position sensor is a common failure in these Jeep engines. 

Q. I bought two new front tires in January. The tires are fine, but Saturday I went to check the tire pressure in the front tires and the valve stem on the left front tire broke in half deflating the tire. We had the car towed and the tire store called and said would it not be covered under the tire warranty. The car is 14 years old, and they told me that replacing the stem is standard practice. They said the part is about $85.00 and with labor it will come to about $115.00. Is that within the normal range and should they have covered the cost of the repair since the valve stem might have been damaged when they replaced the tires?
A. Chances are if the metal valve stem was damaged when the tires were installed it would have failed mush earlier. You have been lucky so far since the typical life of a direct reading tire pressure sensor is seven to 10 years. As for cost the factory sensor (the tire store probably used a quality generic sensor) is about $128 and some shops will charge a minimum of one hour labor to install the sensor, rebalance the tire and program the new sensor. Although $115 is expensive for a valve stem, the price was certainly fair. 

Q. We currently own a 2017 Mazda CX-5 and spend our summers from June through September in Vermont. We are seriously considering a Hybrid SUV. Electric charging stations are not readily available where we live. There are rumors that the elected officials would like to install charging stations throughout the city. It is a 210-mile trip from our apartment to Vermont. A midsize SUV suits our needs, we do a lot of day trips. We are considering the KIA Sportage. We would consider other makes as well and our budget is $40,000. 
A. To me it seems like at least for the near future a plug-in hybrid (PHEV) may be the best choice rather than a full electric vehicle. I recently evaluated the Hyundai Santa Fe. It was in the upper trim level called calligraphy. This model was a plug-in hybrid. It delivered about 30 miles of all electric range with a total range of about 450 miles. For 30 miles of range may your day-to-day driving and although you can charge at any level ll charging station, you can also charge overnight on 120-volt outlet which may work out nicely at your Vermont home. Although slightly smaller the Toyota RAV4 Prime is also a particularly good choice. 

John Paul is AAA Northeast’s Car Doctor. He has over forty years’ experience and is an ASE-certified master technician. He will answer readers’ questions each week. Email your questions to [email protected]. Follow John on Twitter @johnfpaul and friend him on Facebook at mrjohnfpaul.