Hello Scotty, long time sub to your channel looking for some guidance from the expert. I have an old, purchased brand new, 2003 GMC 2500 HD, SLE, auto, w/ approx 145,000 mi. And, it is stuck in the engine reduced power mode and will not move. It had been doing this a long time ago a couple of times but then stopped and corrected itself. It started up again a month or so a few times but about 2 weeks ago it just got stuck in this mode and will not correct itself like before. Can you give me any tips on what I can do? I tried looking on your website but didn't come up with anything. Have you ever run across this issue. I currently do not have any diagnostic tools but have ordered a few on your recommendations but won't have them until the end of the week or hopefully sooner.than later.
The computer has gone into reduced power mode , because it detected a serious problem which could damage the engine. There are several such causes, for example engine knock or severe misfire. If you don't want to wait for your diagnostic tools to come, you could try visiting a store like Autozone or Advance Auto where they usually provide free diagnostic services.
You can also try simple things like check the air filter, spark plugs etc.
Thank you.
If I were a gambling man (I'm not), because of your vehicle type and common issues I suspect when you pull the codes you'll fine an APP (Accelerator Pedal Position) code or a TPS code (Throttle Position Sensor).
The reason I mention it is just to caution you if you do pull one of these codes DO NOT go out and buy a cheap Dorman brand TPS or APP sensor from the auto parts store. Pay the money for an OEM part.
Thank You. I did get a few codes PO120, PO220, PO758, P1516, P1518, P1860 and I will by only OEM parts after I figure out how to go about fixing the problems. How to. Thanks again. {black}:amazed: