Fault codes - P2176 and P1516

[justdennis]

Anyone have any suggestions. I have a 2007 XLR V with 84k miles that I purchased about 5 months ago and have driven very little. A few days ago I went for a short drive and it ran fine, two hours later I started it and it would barely run. I had a few trouble lights on the dash and DIC said reduced power. I guessed it might be the MAF sensor because it had K and N air filters and I know if they have too much oil in them it could coat the MAF sensor and cause problems. So I disconnected the battery, cleaned the MAF and installed new stock filters. An hour later I started it up, took it for a ride and it ran great until the next time I tried to start it. I hooked up a code reader and had two faults, P2176 and P1516, cleared the faults and it ran fine again for a few starts, then the same problem. I can clear the faults and it runs good but the problem comes right back, but only on restart, once it's running it's fine until I shut it off. A little research told me it may have something to do with the actual throttle position not matching where the computer thinks it should be. So, do you think I'm looking at a dirty throttle body, a lose wire connection, a bad sensor or something else.
Any help would be greatly appreciated.
Thanks

 

[mickeytee]

MosT manuals say not to clean the mass air flow or throttle body but there are countless videos on how to do it without damage. The throttle body is fairly cheap and easy to change so cleaning is worth a try. It needs to come off to clean. Then it most likely will need a idel learn reset which is done by a scan repair tool. So maybe line up someone who can do it before you try and clean. If it does not relearn on its on, it will be in limp mode while you go to the garage.

 

[justdennis]

Update
Problem solved, it turned out to be a loose connection on the wires that plug into what I believe to be the top of the throttle body. It is very hard to see and even harder to get your fingers on the connecter but once I discovered that it wasn't snapped in place I was able to work it on a little better. No more codes and the car is running great.

 

[robert.ogden2009]

Great that it was an easy, no cost fix!

 

[justdennis]

Yes it sure could have been a lot worse. I still need to get the connecter locked in place but at least I know what caused the problem.

 

[david12601]

Hi I think i am having the same problem on a 2004.....any chance of a pic of the connector that was loose....thanks

 

[justdennis]

I have the supercharged version so the throttle body is in between the firewall and the supercharger and hidden from view. On the 4.6 in your car I believe it's on the front of the engine so you should be able to see the connector once you remove the beauty cover.

 

[david12601]

Did you have to have a scan tool to reprogram.........i plan on replacing the throttle body and gas pedal.....i have a code scanner but it cannot reprogram.......how do you do a relearn without a scan tool

 

[justdennis]

I have a Tech2 but it was not necessary, once I had a good connection problem solved.

 

[david12601]

Thanks for the reply.....I read on some forums that you need a tool for relearn and others to do a manual relearn ......I think that I will post it on this forum....lhave a nice wveekend

 

[mickeytee]

90% sure you need a tech 2 if you replace a gas pedal. If you just clean or replace the trottle body it should relearn after 4 to 5 driving cycles.

 

[mickeytee]

The factory manual does not state the procedure for reset on the pedal. It however says its very sensitive. Dont bump it, dont tap it,,dont clean it, dont handle with dirty hands etc. Heres a way to do a relearn on the trottle body

 

[david12601]

Thanks for the info......I have a oem new gas pedal assembly and throttle body .......and I plan on starting the car then clear the codes ....disconnect battery......change gas pedal .....change throttle body .....reconnect battery and do the relearn procedure......
Fingers crossed.....thanks for the info

 

[mickeytee]

Give us a follow up on what you find as thats what helps othere with the same problems.

 

[david12601]

Spark plugs changed broke 3 coil connectors ....zip ties to the rescue....1/4 teaspoon of oil in #2and #7 coil well.....replaced cam sensors on bank 1..... replaced gas pedal.....replaced throttle body broke the connector ordered a new one and had to splice it in 6 wires.......hooked up battery went for a 33 mile ride everything seemed ok still have the service ride control message......checked everythin with code reader code po171 lean bank 1 is pending .......
I have to decide about replacing the mag shocks that I bought a couple of years ago or sell them and go with reg with resistors......I dont know if the shocks are good or not as I have nothing to compare the ride too......