: Hi & Help on code's P1120 & P1122

29-03-2009, 20:25

Recently I was told I was going to be made redundant in May. I knew my Company car would be returned either then or if I found another job within the company before that date. Fortunately I have just started a new job for the same company but the company car will be returned forth with !

So decision time, what car next?

My car history off the top of my head latest car first:
BMW 320d Compact
Impreza WRX 276 BHP <!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"> <v:stroke joinstyle="miter"/> <v:formulas> <v:f eqn="if lineDrawn pixelLineWidth 0"/> <v:f eqn="sum @0 1 0"/> <v:f eqn="sum 0 0 @1"/> <v:f eqn="prod @2 1 2"/> <v:f eqn="prod @3 21600 pixelWidth"/> <v:f eqn="prod @3 21600 pixelHeight"/> <v:f eqn="sum @0 0 1"/> <v:f eqn="prod @6 1 2"/> <v:f eqn="prod @7 21600 pixelWidth"/> <v:f eqn="sum @8 21600 0"/> <v:f eqn="prod @7 21600 pixelHeight"/> <v:f eqn="sum @10 21600 0"/> </v:formulas> <v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect"/> <o:lock v:ext="edit" aspectratio="t"/> </v:shapetype><v:shape id="_x0000_i1025" type="#_x0000_t75" alt="" style='width:26.25pt; height:13.5pt'> <v:imagedata src="file:///C:/Users/JAMES%26~1/AppData/Local/Temp/msoclip1/01/clip_image001.gif" o:href="http://forum.astraownersnetwork.co.uk/images/smilies/as/doublethumbs.gif"/> </v:shape><![endif]--><!--[if !vml]-->:thumbs:<!--[endif]-->
Saxo VTR
Rover 220d !
Renault 5 GT Turbo
Peugeot 205 1.6 GTI
Nova 1.4l
Fiat Panda 1.0 4x4 (superb off roader !!!!)

Wanting something quick yet economical I plucked up and bought a 2005 Astra Design 1.9 CDTI 150 and for all of 1 weeks ownership I am already getting problems !

I am running a DTUK Green box which when the car is working its great !

The problem is occurring every now and then.

First time on Sunday cruising at 60 mph approaching a roundabout the engine went into Limp home mode, esp light and eml light (car with spanner) came on, static rev's at around 1500, throttle not making any difference to rev's.

Turned engine off, restarted and fine ! Drove another 10 miles and no problem.

Drove the car 1 day later (Monday) and did a further 20ish miles, no problem at all.

Left then until yesterday (Saturday) and lights on straight away, rev's at 1500 again, throttle not making any difference again.

Turned off, started again no change. Did this 2 more times and on the 4th time no lights running perfect !!

So I have checked the engine codes via the brake and throttle pedal trick and returned 112052 and 112252 or in tech 2 speak:

P1120 Accelerator Pedal Position Sensor 1 High Input C-008
P1120 Accelerator Pedal Position Sensor 1 Low Input C-008
P1120 Accelerator Pedal Position Sensor 1 Range/Performance C-008
P1120 Accelerator Pedal Position Sensor 1 and 2 Signal Incorrect Ratio C-008
P1122 Accelerator Pedal Position Sensor 2 High Input C-008
P1122 Accelerator Pedal Position Sensor 2 Low Input C-008
P1122 Accelerator Pedal Position Sensor 2 Range/Performance C-008
P1122 Accelerator Pedal Position Sensor 1 and 2 Signal Incorrect Ratio C-008

Any help will be gratefully received.


30-03-2009, 07:26
the pedal of the throttle either its out or More likely the plug for the pedal is lose Make sure it is secure because as you described engine stays at 1500 no matter what you do. limp mode will alow you to rev the engine but it wont go past 2000 rpm

so check the wiring for the pedal if it is secured

30-03-2009, 09:13

Will check the connection tonight maybe give it a little spray with WD40.

Anyone else experienced this ?

02-04-2009, 17:14
OK, so I have had the car on a TECH2 and it confirmed the codes

P1120 & P1122

only possible things wrong are wiring or replacing the accelerator pedal which includes the pedal position sensor.

The cost of the pedal has varied over three Vauxhall garages

first 118 + vat = 135.70
second 90 inc vat
third 77 inc vat

The difference is shocking really.

I will get the pedal next week and after fitting will report back if the problem reoocurs.


06-04-2009, 21:07
Ok, new pedal on and no problem as yet !

Hopefully thats it now and that this thread may help someone in the future.


06-04-2009, 23:57
Good to hear you're sorted!!

Let's hope all goes well (Y)

22-05-2009, 19:06
Hello, sorry to bring up an oldish thread.

My Astra 1.7 CDTi 54 Reg has developed the same problem.
So far its happened to me on a dual carriageway, in the fast lane of the M6 on the M56 and at the end of my street. Turning the engine off for a second only worked on 2 occasions.
I had to join the AA and have my car towed 37 miles back home. 135 ish

I took it to a garage who diagnosed it as Pedal sensor 1 and 2.
They changed the pedal and also fixed a problem with the oil pump (something connected to the timing belt as apparently it was hanging off) 350

It happened again the other day on my way to work when I got the end of the street.
Called a mobile mechanic out who has manufacturer specific fault finding software. 20 (instead of 40 because hes my dads mate)
He said it was Pedal Sensor 1 and pedal sensor 2

A guy who works for Vauxhall who's a friend of my dads friend came out to plug his Network Q laptop in. He couldn't get into the ECU. We'd had a power cut in the night, so his laptop hadn't updated over night. He couldn't get into my mums friends ECU on their brand new Astra.
He was supposed to come out on Monday, he phoned to say he'd be late. Never came.
Phone him the next day. He said he's still finishing the other thing off, would be down in a few hours. Never came.

Decided to take it into Vauxhall on Wednesday morning. The guy who should of come down, then phoned saying "I think you should take it to Vauxhall".
Nice one mate, mess me about for 2 days! Pleb! Vauxhall said it would cost 53 just to diagnose the problem.

So now its been in Vauxhall since Wednesday morning and tonight (Friday) we went to Vauxhall at 4 and they hadn't even looked at it. They said "If we don't get chance tonight it'll have to be Tuesday."

I've been without a car for over 2 weeks now and its cost me a fortune so far.

Is it probably just the wiring to the pedal? Or do you think the replacement part was faulty? Or is the ECU shafted?
Has haze20 had any further problems with their car?
I've seen millions of threads on different sites and no one seems to have a direct answer.
Some have said the EGR valve, but the mobile mechanic tested that, its working fine.

Any help is really appreciated.

22-05-2009, 22:55
Hi Jim

Have just done 350 mile round trip to London and around another 500 miles since fitting the new pedal.

It seems to be sorted for me at the moment.

It may be worth considering the throttle body as I remeber that being mentioned. If you locate it try either cleaning or replacement if its cheap enough. Some listings of the obd codes stated throttle sensor position not specifically the pedal.

Hope that helps.

23-05-2009, 15:01
Thanks haze
I'll have a look

12-08-2009, 06:05
Ok, new pedal on and no problem as yet !

Hopefully thats it now and that this thread may help someone in the future.


Hi haze20,
I'm having this problem(P1120 / P1122) intermittenly as well. Mind sharing if the problem ever came back after the throttle pedal replacement


27-08-2009, 02:55
Just an update on my car regarding P1120 and P1122. After changing accelerator pedal sensor and throttle body, i'm still getting the code P1120 and P1122 intermittenly.

Questions(hope some guru here can help)

Q1-Let's say if the camshaft position sensor isn't working well(sometimes ok sometimes faulty) will i be able to start or even drive with these codes pop up.I'm suspecting it's the camshaft sensor or crank sensor.

Q2-I've tried many times on this. When i press the pedal to keep it below 1500rpm(car stationery), no EML error at all. if i press it harder, trying to go beyond 1500rpm, sometimes EML error will come on. If it dosen't, straight away i know the car is ok and it can hold boost and etc.

Any chances Q1 and Q2 could be related?

Thanks in advance for any precious advice or encounter.

30-08-2009, 23:04

Not checked here for a while.

First of all the problem has not come back so changing the pedal worked for me.

The code suggests the pedal & throttle body also but if you have replaced both then I guess the only other thing inbetween is the wiring.

Did you use a new pedal or second hand ?


12-09-2009, 06:35
lastest update on P1120 and P1122.

send in my car to dealer and they found that the ECU (bought a spare ECU with phase 1 programme. used about 2 years) is spoilt.

so revert to my origional ecu and everythings seems to be working fine so far. Except now i have P1105.(car can still boost 0.5bar with spanner light on, but drop to 0.3bar on the higher rpm)

Can someone guide me where to start checking for P1105?
out of curosity, what is the stock pressure setting for Z20LER? i used to have 1.0bar when using phase 1

23-09-2009, 03:13
After changing back to stock ECU i have P1105 present (unable to erase).
1 week later, P1120 resurface again.(Stock ECU)
Send it back to dealer again and request a through check.

Outcome: Found one of the pin from ECU plug in connector is loose.
pin verified and so far there have not had any errors.

This time i am pretty sure the problem is solved becauses previously all the test they have done and come to conclusion, i've done it before.(Have to let them say whatever fault it is, take back the car, let the problem resurface and bring it back to them to prove they are wrong.This process takes times but what to do)