E40 dtc p2101

[Elliott]

I have a Pontiac GTO 2005 LS2 with E40 ECU. Throttle pedal and throttle body all work fine until the Throttle body position reaches 83%....Then the throttle body shuts down and throws DTC code P2101 "Control Module Throttle Actuator Position Performance". With no responce to the padal imput at all. As if the whole pedal and throttle body are dead. Checked the usual stuff like fuses, plugs and wiring etc with no shorts or open ccts. If I clear the Code and turn the ignition off and on again and then it all works fine again until I hit 83% then it all shuts down and throws the same code.... Does anyone have any ideas as to what this might be or how to carry out further testing? I dont just want to buy new components just for the sake of it.

[MyM8V8]

I have a Pontiac GTO 2005 LS2 with E40 ECU. Throttle pedal and throttle body all work fine until the Throttle body position reaches 83%....Then the throttle body shuts down and throws DTC code P2101 "Control Module Throttle Actuator Position Performance". With no responce to the padal imput at all. As if the whole pedal and throttle body are dead. Checked the usual stuff like fuses, plugs and wiring etc with no shorts or open ccts. If I clear the Code and turn the ignition off and on again and then it all works fine again until I hit 83% then it all shuts down and throws the same code.... Does anyone have any ideas as to what this might be or how to carry out further testing? I dont just want to buy new components just for the sake of it.


I have heard of issues with these TB's. Maybe you could try borrowing another actuator to try?

[gmh308]

I have a Pontiac GTO 2005 LS2 with E40 ECU. Throttle pedal and throttle body all work fine until the Throttle body position reaches 83%....Then the throttle body shuts down and throws DTC code P2101 "Control Module Throttle Actuator Position Performance". With no responce to the padal imput at all. As if the whole pedal and throttle body are dead. Checked the usual stuff like fuses, plugs and wiring etc with no shorts or open ccts. If I clear the Code and turn the ignition off and on again and then it all works fine again until I hit 83% then it all shuts down and throws the same code.... Does anyone have any ideas as to what this might be or how to carry out further testing? I dont just want to buy new components just for the sake of it.

This is a factory car/engine/ECM right? Not a conversion or a replacement ECM or pedal?

[Elliott]

Hi, I am unable to borrow another TB unfortunately... The Engine is in a kit car. The ECU, Pedal, TB , Airfolw meter and Engine are all stock items....I have had the engine running wiith no problems and a full throttle responce no problem.....

[gmh308]

Hi, I am unable to borrow another TB unfortunately... The Engine is in a kit car. The ECU, Pedal, TB , Airfolw meter and Engine are all stock items....I have had the engine running wiith no problems and a full throttle responce no problem.....

So the ECM is directly from an LS2 GTO? The problem you describe can occur if the ECM does not have the right GM base level calibration for the pedal and ETC combination.

If you are not sure post your tune file and it can be checked.

[Elliott]

Hiya,

You may have a point the ECU had an Automatic gearbox file on it when I got it. I downloaded a manual tune file for the sme car and year and same calibration number....

Here is the tune file as it is now running...

[gmh308]

Hiya,

You may have a point the ECU had an Automatic gearbox file on it when I got it. I downloaded a manual tune file for the sme car and year and same calibration number....

Here is the tune file as it is now running...

ECM calibrations look fine.

Do you have the part number on the pedal?

And is this with the engine running or engine off?

:)

[Elliott]

Hi

Not sure which on the pedal are the GM Part codes so all the numbers on the pedal are as follows :

AG104798 P0052A013 and XM92188385

This fault occurs with the engine off. Not sure if it occurs with the engine on as have only fired it up in the chassis and run it at idle. I have revved the engine only with light to medium throttle inputs up to about 3000rpm, so not sure if this will repeat itself at full pedal?.... I guess this is somethingI should try :-)

[gmh308]

Hi

Not sure which on the pedal are the GM Part codes so all the numbers on the pedal are as follows :

AG104798 P0052A013 and XM92188385

This fault occurs with the engine off. Not sure if it occurs with the engine on as have only fired it up in the chassis and run it at idle. I have revved the engine only with light to medium throttle inputs up to about 3000rpm, so not sure if this will repeat itself at full pedal?.... I guess this is somethingI should try :-)

The 8 digit number after XM is the GM part number. Looks Ok.

Where are you measuring the 83% number?

Did the ETC/throttle body come with the engine? Looking from the front of the car the motor casing points to the left and is made of alloy like the whole TB? (i.e. if it is a truck TB with a black plastic cover, it wont work.)

What color is the throttle blade?

Also try moving very quickly through the point where you are getting limp and DTC. Try doing this several times and see if the fail effect lessens or goes away.

Does the throttle blade move smoothly and cleanly as you move the pedal slowly?

Also leave it switched on for a while without moving the throttle past 50%. Go away, leave it on. This can have an effect. Learning of some sort.

In the end you may have a faulty TB, but worth trying these points out.

:)

[Elliott]

Hi GMH 308.:-)

Ok...To answer your questions.

83% was read off the dashboard.....For some reason the throttle actuator PIDs on the scan tool would not rgister despite running a realtime test? A bit odd...I will check this out again just in case there is something I am not doing?

Throttle body is the correct TB as you describe. Alloy body not from a truck and it came with the engine.

The throttle blade is a silver metallic colour. The throttle blade moves in proportion to the sweep of the pedal ok. It returns back to the correct start position when the pedal is returned. I Tried the fast sweeps you describe and all works ok but, hold full throttle for approx 1-2 seconds then shuts down and stays down until I clear the codes again??? Do you happen to know the correct voltage that should be present to the TB at full throttle? Maybe it is receiving too much power at the full position and this causes it to overload?

[gmh308]

Hi GMH 308.:-)

Ok...To answer your questions.

83% was read off the dashboard.....For some reason the throttle actuator PIDs on the scan tool would not rgister despite running a realtime test? A bit odd...I will check this out again just in case there is something I am not doing?

Throttle body is the correct TB as you describe. Alloy body not from a truck and it came with the engine.

The throttle blade is a silver metallic colour. The throttle blade moves in proportion to the sweep of the pedal ok. It returns back to the correct start position when the pedal is returned. I Tried the fast sweeps you describe and all works ok but, hold full throttle for approx 1-2 seconds then shuts down and stays down until I clear the codes again??? Do you happen to know the correct voltage that should be present to the TB at full throttle? Maybe it is receiving too much power at the full position and this causes it to overload?

If the throttle blade is not matching the position sensor with +/- 6% that is what is giving you your P2101.

Is the throttle opening almost the whole way? i.e. at WOT on the pedal, is the blade open so it is in the shadow of the shaft?

There are TPS PID's you can check for the voltages and %'s.

It is a stepper motor so it wont overload unless it is jamming for some reason, or not reaching full position when it thinks it should have.


These are from BBL Scan and Tune Drag and Drop Interface. Plenty to choose from. Which are you monitoring. (for some reason these always work better in BBL for us....always inconsistent in scan on PC ? :( )


ECM, ACCEP - PEDAL POSITION 0 - 100%

ECM, APP
ECM, APP_D
ECM, APP_E


ECM, ETCPED

Pedal position sensor:

ECM, ETCPP1
ECM, ETCPP2
ECM, ETCPPS1
ECM, ETCPPS2

ECM, ETCTP - Indicated Throttle Position. (0 - 100% of the expected blade position from memory.)


ECM, ETCTP1
ECM, ETCTP2

Throttle position sensor:


ECM, ETCTPS1
ECM, ETCTPS2


ECM, TAC_PCT


ECM, TADC
ECM, THRA_A
ECM, THRA_B
ECM, THRTIDL_M
ECM, TP
ECM, TPDES
ECM, TPMAX
ECM, TPMIN1
ECM, TPMIN2
ECM, TP_B
ECM, TP_R

[Elliott]

Hi, Fixed it. Taking into account what you had said in your previous answer. I removed the MAF meter to check the throttle blade and to check all the wiring connectors. With the MAF sensor removed I noticed the TB all worked fine, no failure at full throttle?????? I Took a closer look at the inside of the MAF meter and noticed a witness mark on the middle of the inside frame. In short the throttle blade was hitting the inside frame of the MAF meter, jamming against the MAF meter at close to full throttle. I adjusted the position of the MAF meter, slid it a bit more up the TB on its rubber fixing, cleared the DTC codes. BINGO.....Full throttle 88%, no stops, or shut down. Seems the throttle blade was just hitting the inside of the MAF meter, jamming against it, the stepper motor got stuck at this point and shut down.

Thanks for all you replies I have learnt quite a bit from your advice....

[gmh308]

Hi, Fixed it. Taking into account what you had said in your previous answer. I removed the MAF meter to check the throttle blade and to check all the wiring connectors. With the MAF sensor removed I noticed the TB all worked fine, no failure at full throttle?????? I Took a closer look at the inside of the MAF meter and noticed a witness mark on the middle of the inside frame. In short the throttle blade was hitting the inside frame of the MAF meter, jamming against the MAF meter at close to full throttle. I adjusted the position of the MAF meter, slid it a bit more up the TB on its rubber fixing, cleared the DTC codes. BINGO.....Full throttle 88%, no stops, or shut down. Seems the throttle blade was just hitting the inside of the MAF meter, jamming against it, the stepper motor got stuck at this point and shut down.

Thanks for all you replies I have learnt quite a bit from your advice....

Great to hear Elliot. Keep it up and enjoy :).