Resolved "Reduced Engine Power" Message
Thread Starter
Burning Brakes
Joined: Sep 2011
Posts: 871
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From: Alpha/Coopersburg NJ/PA
Resolved "Reduced Engine Power" Message
Hey guys,
For a few weeks, I'd been posting about getting a "reduced engine power" message in my car. It triggered the PCM 1221, 1515, TCS 1278, and occasionally an LDCM and RDCM code. Because of the array of errors, I initially thought it was some sort of electrical problem. Because the dash lights occasionally flickered, I followed a lead suggesting that the ignition switch was going bad and causing other problems. That wasn't the cause of the issue (although it's not flickering now, so maybe that helped) I wanted to post here to explain what it was, and what it wasn't, for the next person searching for this info.
Things it wasn't:
Bad battery
Dirty grounds
Bad ignition switch (but now I have a new one anyway)
Dirty/old air filters (but now I have new ones anyway)
Dirty/bad MAF sensor
What it was: Dirty throttle body.
If I was tackling this issue again, here's exactly what I'd do:
1. disconnect battery, put it in car, take it with you to the parts place for free testing.
2. If it's not the battery, buy injector/TB cleaner, MAF cleaner and electrical contact cleaner. Keep the receipt, get a refund for whatever you don't use.
3. Unhook your air bridge and CAI and clean the TB following instructions online. hook everything back up and restart the car.
4. If that fails, then open the MAF cleaner and use it on the MAF. Make sure your air filters are clean as well.
5. If that fails, then clean the electrical grounds using Curley's great online guides. Might want to pre-buy self tapping ground screws too, those things shear off pretty easy.
6. If that fails, replace the TB or sensors in the TB, depending on budget and comfort with used parts.
My car works great with just the cleaning, run through a whole tank of gas now, problem is 100% gone, idle is smoother than it's been in ages thanks to the clean out of everything.
Seriously, the TB cleaning costs a couple bucks and doesn't take long to do at all. Save yourself $$$$ and do that first when this happens.
Sadly, one of the turn signals burnt out on the way to work today. Oy, well, time to get the tools out again. Till next time!
For a few weeks, I'd been posting about getting a "reduced engine power" message in my car. It triggered the PCM 1221, 1515, TCS 1278, and occasionally an LDCM and RDCM code. Because of the array of errors, I initially thought it was some sort of electrical problem. Because the dash lights occasionally flickered, I followed a lead suggesting that the ignition switch was going bad and causing other problems. That wasn't the cause of the issue (although it's not flickering now, so maybe that helped) I wanted to post here to explain what it was, and what it wasn't, for the next person searching for this info.
Things it wasn't:
Bad battery
Dirty grounds
Bad ignition switch (but now I have a new one anyway)
Dirty/old air filters (but now I have new ones anyway)
Dirty/bad MAF sensor
What it was: Dirty throttle body.
If I was tackling this issue again, here's exactly what I'd do:
1. disconnect battery, put it in car, take it with you to the parts place for free testing.
2. If it's not the battery, buy injector/TB cleaner, MAF cleaner and electrical contact cleaner. Keep the receipt, get a refund for whatever you don't use.
3. Unhook your air bridge and CAI and clean the TB following instructions online. hook everything back up and restart the car.
4. If that fails, then open the MAF cleaner and use it on the MAF. Make sure your air filters are clean as well.
5. If that fails, then clean the electrical grounds using Curley's great online guides. Might want to pre-buy self tapping ground screws too, those things shear off pretty easy.
6. If that fails, replace the TB or sensors in the TB, depending on budget and comfort with used parts.
My car works great with just the cleaning, run through a whole tank of gas now, problem is 100% gone, idle is smoother than it's been in ages thanks to the clean out of everything.
Seriously, the TB cleaning costs a couple bucks and doesn't take long to do at all. Save yourself $$$$ and do that first when this happens.
Sadly, one of the turn signals burnt out on the way to work today. Oy, well, time to get the tools out again. Till next time!
Last edited by Endeka; Apr 2, 2014 at 04:47 PM.
