PCM had to be replaced

[cs1992]

In another post, I explained that my Check Engine Light came on last week and the transmission was shifting hard. Ends up that the computer (PCM)had to be replaced. With only 12k miles on the car, I am not impressed. Anyone else ever have PCM issues?

[Raven]

There were a lot of PCM replacements because of hard starting. There was a TSB for the '05 I believe.

[blue_can]

Unfortunately the yield from the manufacturing process is not always 100%. Unless the PCM has an identifiable issue with loss of control to the pressure solenoid you may have just been unlucky. Most manufacturing processes follow the Gaussian Probability Distribution Function so if you happen to fall on the wrong side of the curve the probability of a failure goes up. It may have just been an isolated thing. As for the actual fault it may have been something simple like a dry joint on the circuit board. Faults with ICs are really not common.

[chevelle_lover]

Sometimes when the motor is warm when I go to start the motor it takes an extra couple of seconds of cranking to start the motor. Is this the problem with the PCM that they are taking about. If normally it takes 2-3 seconds of cranking to start the motor then this takes 6-8 seconds to start the car.ThanksMike

[northvibe]

Quote, originally posted by chevelle_lover »Sometimes when the motor is warm when I go to start the motor it takes an extra couple of seconds of cranking to start the motor. Is this the problem with the PCM that they are taking about. If normally it takes 2-3 seconds of cranking to start the motor then this takes 6-8 seconds to start the car.ThanksMikeThat I think may be the heat soak issue, in which the ecu was usually replaced if im not mistaken.... check thesehttp://forums.genvibe.com/zerothread?id=20634http://forums.genvibe.com/zerothread?id=23348

[luggnutz65]

Hi, I have a 2006 Vibe... the same exact thing just happened to me tonight. The Check Engine light came on followed by the car shifting very hard. I haven't had time to check it out yet. Is the PCM expensive. Oh yea, the car has 36,7** miles. Just over warranty. Is the Pressure control solenoid inside the xmission or is it accessible from the outside? I am going to go after this problem myself since the warranty came up, and it's kind of fun granted it doesn't cost too much! Thanks for your help.

[blue_can]

The pressure control solenoid is inside the transmission - you need to take out the valve body to get to it. If you are going to go after it yourself get an oscilloscope and check for the pressure control solenoid pulses at the shift solenoid connector - if they are not there the problem is likely the PCM - if not it may be a faulty solenoid. You can also check the solenoid coil for continuity with a multimeter.

[northvibe]

oh oscilloscopes turn me on! used them all in college...nice

[blue_can]

LOL..do you like the nice patterns. They have some nice hand held ones for debugging automotive problems but they are quite expensive. I was looking to buy a "lunchbox" type one for home use but I believe they cost over 10K. If I need one I usually borrow one from work.

[northvibe]

we had some new ones that were nice with nic connections, but the other ones had the wave shot to the screen so they got burn in lol...ohhhh love it. had good times in signals and systems.

[blue_can]

Cool. I use them frequently as I work in R&D developing integrated circuits (chips) - mainly for wireless and satellite equipment.

[x10]

Hey Fluke scopemeters have came way down in price and Tektronix has a low end bench model that is great for the moneyhttp://www.tek.com/Measurement...es_enTDS1000B and TDS2000B Series OscilloscopesI have used this one and it does a great job for $850, I use O'scopes daily and while I use much higher priced scopes this scope for automotive applications will do the job, Most of the time you don't need to look at Fast transients for General troubleshooting so the 40mHz bandwith won't kill you, But it does have usb, Dump your screen as an image or a CSV fileI've use a fluke scope meter for years and Its a bit more portable but the lcd screen sometimes is a bit hard to see in bright sunlight plus the older ones don't have usb

[blue_can]

Yes, I did look at a few used scopemeters online as well as ebay (used) and saw quite a few at reasonable prices. I agree for automotive applications you really do not need much bandwidth unless trying to trace a spurious glitch which is more likely to happen during the design of the product. One would hope this kind of issue would have been resolved by the time the product is selling.