07 LS P0121 problem.

[llllljrlllll]

I was driving today when all of a sudden my cel came on, hooked up the obd and it gave me this code P0121, does anybody know how to fix this? Or is it part of the powertrain 100k coverage, so I can have the dealer fix it. Any advice would be appreciated. Thanks

 

[zach2011]

A code P0121 may mean that one or more of the following has happened:

* TPS has intermittent open or short internally
* Harness is rubbing and causing an open or short in the wiring
* Bad connection at the TPS
* Bad PCM (less likely)
* Water or corrosion in connector or sensor

Possible Solutions

1. If you have access to a scan tool, see what the idle and WOT (wide open throttle) readings are for the TPS. Check if they're close to the specifications mentioned above. If not, then replace the TPS and re-check.

2. Check for an intermittent open or short in the TPS signal. To do that, you can't use a scan tool. You'll need an oscilliscope. The reason is because scan tools take samplings of many different readings over just one or two data lines and can miss an intermittent drop out. Hook up your oscilliscope and watch the signal. It should sweep up and down smoothly with no drop outs or spikes.

3. If no problems were noticed, perform a wiggle test. Do this by wiggling the connector and harness while watching the pattern. Does it drop out? If so, replace TPS and re-check.

4. If you have no TPS signal, check for 5 Volt reference at the connector. If it's present, check the ground circuit for open or shorts.

5. Make sure the signal circuit isn't 12V. It should never have battery voltage. If it does, trace circuit for short to voltage and repair.

6. Look for any water in the connector and replace TPS as necessary.

 

[llllljrlllll]

What!!!!!!!!!!!!!!!!!!!!!!! zach you the man, but can you translate this in English. Do you know if this is covered by the 100k power train warranty. Thanks for the quick response

 

[zach2011]

I have no idea where the TPS is located, I think it is in a complex area that the dealer will have to search for. They will know if it is covered, just call and ask. TPS stands for Throttle Positioning System, so maybe that will help translate it to English haha.

 

[EB1]

P0121 Code

After my CEL came on recently I scanned and got a P0121 code. I've searched on the forum and there doesn't seem to be any clear resolution to this code. Is this problem as simple as buying a new TPS and replacing it? Anybody know the cost on this part? Is this the only possibility or could the real problem be with something else?

 

[KMeloney]

Isn't the TSP the Throttle Position Sensor? If so, it's the electronic thing atop/along side the MAF that detects how open the thottle is. Seems to me that a point drags across a coil and measures throttle position. Might just be a replacement of that part, which I can't imagine is really expensive. But, I'm not a tech, so I don't know for sure...

 

[EB1]

I appreciate the help, KMeloney, but that much I already know. jr and a few other guys on this forum have actually experienced the EXACT SAME problem... and I don't want to waste time and money stabbing in the dark at an issue. I want to know exactly which part to replace. Yeah, I'm fairly sure it's the TPS, which I'm also fairly sure is bolted directly to the throttle body. ---- The P0121 code also says something about throttle "pedal" position sensor, so I want to make sure it's not a sensor on the pedal itself. So again, some direction from someone who has remedied the P0121 code would help. Thanks.

 

[KMeloney]

Got it. Haven't had the problem, so I'm still useless. Good luck!

 

[EB1]

Throttle Position Sensor

Any ideas on this from anybody else?

 

[lowAZhoe]

Probably needs a throttle body. Will be covered under powertrain warranty.