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Dtc P0121

ussygussy

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ussygussy Enthusiast

ussygussy

Posted
Posted

Hi everyone! Newbie here. :puke:

 

I tried searching the forums for an answer to my question, but haven't had any luck. I'm hoping you kind gents will help me out! This morning, my CEL came on and I just so happen to have a OBDII scanner in my BMW. I pulled the codes and it said I have two (2) P0121.

 

I googled it first and found one answer:

 

P0121 - Throttle Position Sensor A Circuit Range/Performance

 

And then I found another one:

 

P0121 - TPS Voltage Does Not Agree With MAP TPS signal does not correlate to MAP sensor signal.

 

Which one is correct? I have 71,000 miles on it and have a warranty til 100,000. Will this be covered?

 

Any help would be greatly appreciated it!

DofD Senior Enthusiast

DofD

Posted
Posted

Yep, time for a trip to the dealer for some warranty service.

 

BTW... Hi there and welcome to GM Trucks!

alaska511 Senior Enthusiast

alaska511

Posted
Posted

 

Awesome! Thanks a bunch! Is this a serious issue or can I drive the car for a few days?

 

Yep, time for a trip to the dealer for some warranty service.

 

BTW... Hi there and welcome to GM Trucks!

 

:thumbs: Hi! Thanks!

 

 

 

It depends, if the circuit opens, or the potentiometer opens, then you will only have idle speed.

ussygussy Enthusiast

ussygussy

Posted
  • Author
Posted
It depends, if the circuit opens, or the potentiometer opens, then you will only have idle speed.

 

Well after I drove for a bit, it went away...and then it came back :thumbs: Sound serious?

minibike132 Senior Enthusiast

minibike132

Posted
Posted

 

 

That's for a 2000 F body, The circuits are not alike in any way.

As far as the OP question goes the code descriptions are both correct they just go about 2 different ways of describing the issue. The PCM compares the map and the TPS, they should basically mirror eachother. If you open the throttle there should be an equal response in manifold air pressure. If there is not the code sets. There can be alot of reasons for this. Plugged exhaust, if the air can't get out it can't get in as fast as it is asked for. Vacuum leaks, obviously if there is a leak before the cylinder there will be a difference in requested position and actual pressure (or vacuum). Or there can be all the multitude of electronic issues being one or the other of the sensors is bad or the PCM or the wiring related to the circuits. There really is no easy way of telling and you are under warranty so it's really not worth investigating here. Take it in and let that insurance money pay itself off.

alaska511 Senior Enthusiast

alaska511

Posted
Posted
It depends, if the circuit opens, or the potentiometer opens, then you will only have idle speed.

 

Well after I drove for a bit, it went away...and then it came back :thumbs: Sound serious?

 

 

 

Hard to say, just take 'er in when you get a chance.

ussygussy Enthusiast

ussygussy

Posted
  • Author
Posted

 

 

That's for a 2000 F body, The circuits are not alike in any way.

As far as the OP question goes the code descriptions are both correct they just go about 2 different ways of describing the issue. The PCM compares the map and the TPS, they should basically mirror eachother. If you open the throttle there should be an equal response in manifold air pressure. If there is not the code sets. There can be alot of reasons for this. Plugged exhaust, if the air can't get out it can't get in as fast as it is asked for. Vacuum leaks, obviously if there is a leak before the cylinder there will be a difference in requested position and actual pressure (or vacuum). Or there can be all the multitude of electronic issues being one or the other of the sensors is bad or the PCM or the wiring related to the circuits. There really is no easy way of telling and you are under warranty so it's really not worth investigating here. Take it in and let that insurance money pay itself off.

 

 

Thanks! Hopefully it isn't a big issue. I just emailed my local dealership to set up an appointment. I hope they can get me in on Monday.

alaska511 Senior Enthusiast

alaska511

Posted
Posted

 

 

That's for a 2000 F body, The circuits are not alike in any way.

As far as the OP question goes the code descriptions are both correct they just go about 2 different ways of describing the issue. The PCM compares the map and the TPS, they should basically mirror eachother. If you open the throttle there should be an equal response in manifold air pressure. If there is not the code sets. There can be alot of reasons for this. Plugged exhaust, if the air can't get out it can't get in as fast as it is asked for. Vacuum leaks, obviously if there is a leak before the cylinder there will be a difference in requested position and actual pressure (or vacuum). Or there can be all the multitude of electronic issues being one or the other of the sensors is bad or the PCM or the wiring related to the circuits. There really is no easy way of telling and you are under warranty so it's really not worth investigating here. Take it in and let that insurance money pay itself off.

 

 

:thumbs:

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