Throttle Body Cleaned, now reduced power light?

[NT1078]

Hi All,
Hopefully this is an easy one. Today I cleaned the Throttle Body on my Envoy. I disconnected the positive terminal from the battery during the entire process. Just took it for a test drive and it ran great for a few minutes, then the Reduced Engine Power lamp came on, with a Check Engine. I don't have a code reader, my guess is I did not allow the PCM to learn the new setting since cleaning.

I should mention that if when I shut the truck off and restart, it runs great for a minute or two, then the Reduced Power comes on again.

Do I disconnect the battery again to reset, or am I best to pull the two PCM fuses?

Thanks in advance,
Adam

 

[dmanns67]

I would not recommend disconnecting the battery to clear the code. Swing by AutoZone or Advanced Auto to have the code read. Once you have the code you can search and get assistance from members here. Better yet pick up a ELM327 and download the torque app on Android. The ELM327 will connect to the OBDII port. You will be able to read your own codes and clear them once repairs are made. You can also see live data with the app. Well worth $20 (amazon.com)

Typically I pull the (2) PCM fuses for about 20-30 min when I clean the throttle body instead of disconnecting the battery.

What type of cleaner did you use on the throttle body, carburetor or throttle body cleaner?

 

[NT1078]

I used a spray engine degreaser and went at it with a tooth brush, then wiped everything down thoroughly with a rag when completed. I will try to have the code read today. Supposed to be going camping tomorrow morning, so I hope I can get this resolved this evening!

 

[KNBlazer]

I used a spray engine degreaser and went at it with a tooth brush, then wiped everything down thoroughly with a rag when completed. I will try to have the code read today. Supposed to be going camping tomorrow morning, so I hope I can get this resolved this evening!

You should have used a throttle body cleaner, not a degreaser... and disconnected neg battery cable first if you were going to disconnect positive...

 

[HARDTRAILZ]

If you let it sit and idle, is it smooth or does it stutter? Does the light come on if just idling?

Double check you have everything seated and bolted right. Hoses n sensors. Sometimes its easy to think you got it, but something is just a bit off.

 

[The_Roadie]

Being able to read codes is a critical tool in any DIYers kit on all modern vehicles. But since the throttle body was the thing worked on, I'm guessing the most likely thing is a disagreement between the two sensors that report back the butterfly valve position to the PCM. And that could be from damaged wiring to the throttle body, a flaky, loose, or out of position pin in the connector, or coincidental damage inside the throttle body sensor assembly itself. Assuming you didn't drop the throttle body during cleaning it, I'd be examining the wiring harness and connector pins very closely.

 

[NT1078]

Being able to read codes is a critical tool in any DIYers kit on all modern vehicles. But since the throttle body was the thing worked on, I'm guessing the most likely thing is a disagreement between the two sensors that report back the butterfly valve position to the PCM. And that could be from damaged wiring to the throttle body, a flaky, loose, or out of position pin in the connector, or coincidental damage inside the throttle body sensor assembly itself. Assuming you didn't drop the throttle body during cleaning it, I'd be examining the wiring harness and connector pins very closely.

Okay, I will go over everything when I get home today. Should I unplug the two fuses for the PCM first for a reset?

 

[dmanns67]

Okay, I will go over everything when I get home today. Should I unplug the two fuses for the PCM first for a reset?

I would pull the fuses then go from there. Make sure everything is back together correctly.

 

[smt 59]

Buy yourself some throttle body cleaner(that's why they make it) and go over the process again,the degreaser will leave a film and do not use a brush the cleaner will do all the work for you, a soft cloth for final clean up is all you need. Although this part is metal it is very sensitive. Wiring is also an area that you must be extremely careful.

 

[dmanns67]

Buy yourself some throttle body cleaner(that's why they make it) and go over the process again,the degreaser will leave a film and do not use a brush the cleaner will do all the work for you, a soft cloth for final clean up is all you need. Although this part is metal it is very sensitive. Wiring is also an area that you must be extremely careful.

Good point and throttle body specific cleaner is relatively cheap. I have been using CRC's tb cleaner for years. I also use a soft bristled toothbrush and a microfiber towel when cleaning. Some deposits are stubborn and need the toothbrush to scrub them off.

 

[gmcman]

You didn't by chance pull any coil pack wires before you hosed the engine down? I don't think the coil pack sockets drain so just something that comes to mind.

Also, did you tug or wrestle with the TB connector when removing? I had the same issues with one of the wires being loose.

 

[smt 59]

Good point and throttle body specific cleaner is relatively cheap. I have been using CRC's tb cleaner for years. I also use a soft bristled toothbrush and a microfiber towel when cleaning. Some deposits are stubborn and need the toothbrush to scrub them off.

Same product I use, great stuff.

 

[Mark20]

The throttle body cleaners are supposed to safe for the electronics in them. I have carb cleaner on hand but when I first cleaned my Voy's throttle body I decided to buy the proper cleaner to be on the safe side.

 

[Mounce]

Pretty sure I used some that was marketed as "throttle body and carb cleaner." Didn't have any trouble and I didn't do the relearn deal, I have only heard of that twice and there wasn't any info on how to do it. I just cleaned it then drove it on a 400 mile trip and never had any trouble.