P0121 fault log

[Smallholdertoo]

I acquired a 2014 Superb 4x4 2.0tdi 140 about a month ago. Its start stop has not worked other than when charged by the garage that sold it to me. (they are now going to replace the battery as it should already be fully charged as I drive 100 miles a day). It has also had an intermittent P0121 fault, which the garage had thought was due to their power washing of the engine. This reoccurred last night after a couple of weeks.It does not appear to go into limp home mode. Ps it did chuck it down last night.

 

It is due back at the garage on Thursday for the replacement battery and the EML.  Any ideas what could cause the engine management light come on.

 

I attach the VCDS print.

 

Address 01: Engine (J623-CFFB) Labels:. 03L-906-018-CFF.clb
Part No SW: 03L 906 018 SA HW: 03L 906 018 MH
Component: R4 2.0l TDI H28 9978
Revision: 41H28--- Serial number:
Coding: 00190012042701080000
Shop #: WSC 17025 210 00000
ASAM Dataset: EV_ECM20TDI01103L906018SA 003006
ROD: EV_ECM20TDI01103L906018SA.rod
VCID: 7BDB261AF2F7439EDF-802E
1 Fault Found:
5286 - Throttle Position Sensor (G69)
P0121 00 [232] - Implausible Signal
MIL ON - Intermittent - Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 2
Mileage: 74645 km
Date: 2017.08.20
Time: 18:34:29
Engine speed: 139.00 /min
Normed load value: 100.0 %
Vehicle speed: 0 km/h
Coolant temperature: 89 °C
Intake air temperature: 16 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 12.940 V
Unlearning counter according OBD: 40
Air mass: actual value (mg/stroke): 467.6 mg/stroke
Throttle valve adapter: specified value: 0.00 %
Throttle valve adapter: actual value: 2.33 %
Throttle valve adapter: offset closed: -11.79 %
Throttle valve adapter: status-Bit 0: 00000000
Throttle valve adapter: status-Bit 16: 00001000
Throttle valve adapter: status-Bit 24: 00110111
Throttle valve adapter: status-Bit 8: 00000010
Throttle valve adapter: uncond voltage actual value: 1016.4 mV
Readiness: 1 1 0 0 0
-------------------------------------------------------------------------------

SUPERB V3A.pdf

Edited 21 August, 2017 by Smallholdertoo
add age of car

[peter_k]

Nothing to help you but "Engine speed: 139.00 /min" looks wrong.

[Jhr8686]

Did your fault get fixed? What was the outcome as I am experiencing this fault also and out of warranty so was wondering if I could fix it simply by myself.

[LightRain]

1 hour ago, Jhr8686 said:

Did your fault get fixed? What was the outcome as I am experiencing this fault also and out of warranty so was wondering if I could fix it simply by myself.

As a first step you could check the throttle body physically. Unplug the connector, check for corrosion or dirt, replug and check the cable as much as you can see for visual signs of damage or contamination.

 

Is yours the same age and engine? If you have a VCDS readout share it with us.

[Jhr8686]

I will check those things 1st. It is a 2013 2l diesel 170bhp 4x4. So I think the same. 

 

Don't have a few read out only diagnosed fault with cheap OBD reader which showed p0121 and nothing else. 

 

I take it you mean on the mechanical throttle body within engine or the pedal itself? 

[LightRain]

46 minutes ago, Jhr8686 said:

I take it you mean on the mechanical throttle body within engine

Yeah.

It probably won't help, but it's a good first step before things get more in depth.

Edited 2 November, 2017 by LightRain

[Jhr8686]

I checked all the wiring as much as could be seen. And cleaned all the contacts. The accelerator pedal was feeling stiff compare with a friends superb so ordered a new pedal and fingers crossed fault has not appeared again since this new part. Thanks for help. 

[9@zA]

On 17/11/2017 at 12:07, Jhr8686 said:

I checked all the wiring as much as could be seen. And cleaned all the contacts. The accelerator pedal was feeling stiff compare with a friends superb so ordered a new pedal and fingers crossed fault has not appeared again since this new part. Thanks for help. 

Hi boss

 

You changed the peddle 4 months ago,  is all OK ? Hopefully the fault has not reappeared.  Let us know please.  Thanks 

[Jhr8686]

Sorry yeah after changing the pedal and cancelling fault with obd plug it has not reappeared. Touch wood. 

[9@zA]

2 minutes ago, Jhr8686 said:

Sorry yeah after changing the pedal and cancelling fault with obd plug it has not reappeared. Touch wood. 

Excellent.  Thank you 

[9@zA]

9 hours ago, Jhr8686 said:

Sorry yeah after changing the pedal and cancelling fault with obd plug it has not reappeared. Touch wood. 

Sorry completely forgot to ask,  was the peddle plug and play or it needed adaptation with vcd.  Thanks 

[9@zA]

On 28/03/2019 at 21:15, Jhr8686 said:

Sorry yeah after changing the pedal and cancelling fault with obd plug it has not reappeared. Touch 

[PipH]

9@zA this original post refers to fault code P0121 which is a Throttle Position Sensor fault & nothing to do with the accelerator pedal.

 

Think you will need a code read before splashing out on parts.

[Jhr8686]

Yeah pedal was plug and go I didn't need to do anything else. I hope it worked for you. As for the throttle body within the engine I never touched this or cleaned it just changing the pedal stopped the fault code repeating. As PipH said could be throttle itself but in my case new pedal was all it took. 

[9@zA]

On 14/04/2019 at 13:47, Jhr8686 said:

Yeah pedal was plug and go I didn't need to do anything else. I hope it worked for you. As for the throttle body within the engine I never touched this or cleaned it just changing the pedal stopped the fault code repeating. As PipH said could be throttle itself but in my case new pedal was all it took. 

Hey JHR8686 . Confirmed fix !  Replacing the pedal and cancelling ( The mechanic insisted to cancel the code ) fault code has fixed the P0121issue for me too.  Thanks for sharing your experience. 

 

 

Edited 19 April, 2019 by 9@zA
Update

[9@zA]

 

On 13/04/2019 at 12:18, PipH said:

9@zA this original post refers to fault code P0121 which is a Throttle Position Sensor fault & nothing to do with the accelerator pedal.

 

Think you will need a code read before splashing out on parts.

For me it was the pedal itself.  There is a sensor inside the pedal and upon replacing it solved the problem.  Bought one off eBay £15 ( No word of lie) 

 

But yes could be many other reasons in regards to P0121. 

Edited 19 April, 2019 by 9@zA
Update

[Juhagpl]

Hello Guys,

so do i understand correctly that i need to replace the throttle pedal? This is what came some days ago....

[DEL80Y]

@Juhagpl

Can also be throttle body needing cleaned

Ecu thinks bad signal from pedal due to throttle not opening correctly 

They carbon up and dont go to full open

read the thread above its got all the info on the modification to it as well😎

 

Edited 1 June, 2020 by DEL80Y

[Juhagpl]

Thank You!