P0121 Throttle / Pedal position sensor

[shakermikee]

Has anyone else had this problem?

I keep getting an intermitent engine management light on (VXR8 LS2) with no side effects to the car (eg limp mode) it drives exactly as it always does, either with light on or off.

Had a diagnostic plugged in and came up with the code 'P0121 Throttle / Pedal position sensor'

I have done some searches and coming up with a few different answers, some are saying the sensor wiring could just be loose, others say the sensors are within the throttle body and you need to replace the full part.

I found a part number of 12570790 and spoke with Monkfish, they confirmed this is the correct part number for a throttle body and costs £236.

Just wanted to check if anyone had similar experience before I buy the part and get it fitted.

[ringram]

Leave the code triggering for diag's but turn off the MIL.
You wont get annoyed by it then.

[moif]

Hi Mike,mine was doing the same BUT going into limp mode,did it 3 times in a fortnight,the code i was getting was P2101 which relates to the actuator,anyway a new throttle body needed which now have a mod done to them,i'll be fitting it tommorrow

[shakermikee]

Hi Moif. Where did you get your throttle body and what is the mod done to it?

[moif]

shakermikee said:

Hi Moif. Where did you get your throttle body and what is the mod done to it?

Got it from the Fish via the states,the mod is something to do with the harness that comes with it,Andy told me i must use the one thats attached to the new TB,but to what the mod is i dont know

[shakermikee]

Cheers, will speak further with Monkfish before ordering.

[monkfish1]

moif said:

shakermikee said:

Hi Moif. Where did you get your throttle body and what is the mod done to it?

Got it from the Fish via the states,the mod is something to do with the harness that comes with it,Andy told me i must use the one thats attached to the new TB,but to what the mod is i dont know

The mod is to the throttle body itself, something we had to do as part of the recent work we did with the cam installation. If you just put a standard TB on, it wont run very well now! Doesn't/wont help the OP at all.

[ringram]

Shouldnt need to touch the throttlebody for a cam install.. tune will sort it out.
Found that out after much tune messing and discussions with the powers that be at PRI/SEMA etc.

[shakermikee]

monkfish1 said:

The mod is to the throttle body itself, something we had to do as part of the recent work we did with the cam installation. If you just put a standard TB on, it wont run very well now! Doesn't/wont help the OP at all.

Hi Monkfish. With the problem I am getting is it likely a new throttle body will fix it?

As per my original post the car is running fine with or without the intermitent EML related to this code/fault.

Just wondered if there are any checks that can be done, to ensure that a new TB is required rather than something else.

[EssexVXR8]

Check all your potentiometer tracks

[monkfish1]

shakermikee said:

monkfish1 said:

The mod is to the throttle body itself, something we had to do as part of the recent work we did with the cam installation. If you just put a standard TB on, it wont run very well now! Doesn't/wont help the OP at all.

Hi Monkfish. With the problem I am getting is it likely a new throttle body will fix it?

As per my original post the car is running fine with or without the intermitent EML related to this code/fault.

Just wondered if there are any checks that can be done, to ensure that a new TB is required rather than something else.

P0121 is the throttle position switch greater than 9% adrift of the other. This is normally a defective throttle body, as thats the smallest servicable part available.

To answer your question directly, its likely that it will fix it, but not certain. It could be wiring or PCM related too.

Edited by monkfish1 on Friday 14th December 14:52

[Throwyourbike]

I replaced the throttle body on my LS2 Monaro a couple of months ago. The fault only happened once every few weeks to begin with but it got more frequent to the point where the car wouldnt even turn over.

[stussy2000]

May I point you to this thread...that was another one of my codes:

www.hsv.org.uk/topic.asp?t=1201805&f=69&h=27

[moif]

monkfish1 said:

moif said:

shakermikee said:

Hi Moif. Where did you get your throttle body and what is the mod done to it?

Got it from the Fish via the states,the mod is something to do with the harness that comes with it,Andy told me i must use the one thats attached to the new TB,but to what the mod is i dont know

The mod is to the throttle body itself, something we had to do as part of the recent work we did with the cam installation. If you just put a standard TB on, it wont run very well now! Doesn't/wont help the OP at all.

Apologies for the misunderstanding