Still chasing the infamous T/C - Hard Shifting issue.... I've replaced the intake and exhaust solenoids, checked all plug connections, fuses, etc, etc..... I've checked for any current or previous codes with none to pull.

This in a 06 / 2.4 - auto / 2LT.

The T/C seems to come on under hard acceleration only so this evening, with the trans in Neutral, I snapped the throttle a couple times and on came the T/C light...... I'm curious if anyone else has tried this and if so, could it be a Mass Air Flow Sensor?

Any help is always appreciated!!!!

 

Until you can download a CEL code, any suggestions would be a "guess" - meaning you will likely just keep throwing $'s at the issue.

Yes, it might be a problem with the MAF, - but also might be a problem with the MAP sensor, or............. a mess of other things.

Without a code, it's likely best so see a dealer who can throw one of their fancy analyzers on it to help determine the problem.

 

X2. You will need a scanner that will read codes other than just emission codes. It may need a diagnostic by reading sensor values not just codes.

 

I have been chasing this problem for many, many years (since 2006). In my case, it is hard to pinpoint exactly when it began. I put on a CGS intake, had my computer reprogrammed, then a few days later my car got hit directly at my right back wheel. When I got the car back from the shop, I noticed that if I did a burn out, I threw the T/C code. My Chevy dealer refused to look into it, blaming it on my intake mod. As time went on, the problem got worse. The car coded when just stepping on the gas hard. Now, it comes on for now apparent reason. I could be driving at a steady speed (city or highway) and suddenly the light comes on.

I have tried everything-changing the MAP and MAF sensors, unprogramming the computer tune, checking for loose fuses and wires, replacing the air filter with a dry one that doesn't need to be oiled, etc. Lately I have heard that this problem also happens on stock, non modified HHR's.

Any ideas on how to fix it would be greatly appreciated.

 

Just happened again. I was driving at about 20 mph without touching the gas pedal and all of a sudden the T/C light popped on. What gives?

 

Some theorize a hub speed sensor. Sound like could be from the accel parts of the pronlem. If the hubs don't agree with each other and the trans speed, the TC thinks it needs to work.
If it was a MAF the CEL would light up.

 

I always suspected it was the speed sensor-especially in my case since mine was hit in the crash. Can it be checked or does it have to just be replaced?

 

All of them (4) are integral with the hub/bearing. There probably is a spec to check, but I don't know. I's start by unplugging and replugging all of the sensors, while inspecting the leads for damage. That's about all I got on the subject.

Nobody ever thinks about the rear hubs. They are real easy to replace, once you get the drums off, just 4 bolts, don't even have to take the shoes off.

 

Thanks Don, I will check into it.

 

Spoke to dealer on this issue and was told it would be hard to trace any type of code without CEL or the T/C light on...... I find it hard to believe that this could be an issue with my wheel speed sensors since I am able to trip the T/C light on sitting in my driveway in "Park" or Neutral" and by simply revving the engine, have the light come on.....
I've heard that installing a K&N filter causes the MAF Sensor to trip this light? Again, this should trip the CEL light but then again, why have we all replaced our intake and exhaust selonoids while chasing the T/C issue??????