I hate to say it but this thread is about a issue everyone with a Sky WILL have so you need to read and remember this.
Over the past few weeks my car (07 Base) with a lot of mods as most of you know, has a couple very frustrating problems. Now with 92,000 miles on my car and a daily driver, the guys at the Dealer call it their test car for problems they will see in time.
Reduced Power Mode & hard starting.
The hard starting is easy. Its most likely the EVAP "Evaporation Purge Valve" That you can check very easily. The valve is right behind the valve cover on the 2.4's Its on the intake manifold on the 2.0. If you watch the video below that Dave and the crew up at DDMworks made of the 2.0. The tubes come off the same way. Thanks Dave
The best way is to unplug it first then push the center tang of the clip down that is holding it in place and pull it forward to get it off the bracket then you can get it up high enough over the back of the valve cover to get the tubes off. This valve Prices out at 14.00 online to $44.00 at the dealer.
As far as the limp "Reduced Power" mode here is what I did before finding the fix which has taken 4 months!
I tried unplugging every Engine compartment connectors, cleaned them, put di-electric grease on all of them and plugged them back in. It would be ok for anywhere from 2 days to 2 weeks and would do it again. Every time this would happen I would open the hood, move a few wires around or unplug the throttle body connector and it would go away even tho I had to unhook the battery to clear the amber light.
This went on for weeks on and progressively getting worse. The connector at the throttle body felt kind of strange so I pulled all the pins out, clipped a little wire off the end then soldered then back instead of crimping new pins on.
Well as usual now light and good for 2 days then did it again.
I had taken it to the dealer before to check it but they said it could be any of the connectors causing it but they couldn't tell which one but this time it was so bad they narrowed it down to the c100 harness.
Here is where it gets good. They couldn't clear the codes so they knew it was a completely disconnected wire or pin. After unplugging the C100 harness and plugging it back in all codes cleared and it ran great.
I had already had it apart once my self so once they did it and it cleared we knew that was the problem. I already had the wiring diagram but was not sure which wires would cause it. The Technician was great and we sat down and went over the wiring. He showed me which wires causes this problem because they are the only wires in that harness that talks between the gas peddle position sensor, then to the ECM and finally up to the throttle body.
HERE IS THE KICKER! GM does not sell this harness and the only fix it to pull out the connector on both sides of the plug and hard wire (solder) them together.
This is going to be a issue on every one of our cars
because these very small pins wear due to vibration and eventually loose there connection.
If you know how to fix this it will save you $300.00 at the dealer. and NO MORE LIMP MODE due to the throttle circuit
Below are some pictures I took of the process. The first picture is where the connector is located the rest are of how I did it then final tape and reinstall. It is under the metal bracket and you have to take the inner fender off to do the job.
If any of you need the drawing and pin positions just let me know and I post the drawings on here.