Another Hard One :-(

[A3 T]

Not that....lol


I was driving down a quite road today (so not driving fast) when all of a sudden the revs started pulsing and the accelerator pedal stopped working completely.

I pulled over to the side of the road and used my generic fault code scanner i have linked to my iphone and it gave these codes:

Stored Codes

P0223
Throttle/Pedal Position Sensor/Switch “B” Circuit High


P0223
Throttle/Pedal Position Sensor/Switch “D” Circuit High


P0223
Throttle/Pedal Position Sensor/Switch “E” Circuit High



Pending Codes

P0135
O2 Sensor Heater Circuit Bank 1 Sensor 1

P0138
O2 Sensor Circuit High Voltage Bank 1 Sensor 2


So i called the breakdown company and when the guy eventually showed up he just had a quick look and said “i hate electrics” “where do you want me to take it”.


When i got home i ran vagcom on it and got this:


Address 01 -------------------------------------------------------
Controller: 06A 906 032 HJ
Component: 1.8L R4/5VT 0002
Coding: 11500
Shop #: WSC 00000
WAUZZZ8L52A001557 AUZ5Z0A5293082
5 Faults Found:
18039 - Accelerator Position Sensor (G79): Signal too High
P1631 - 35-00 - -
18042 - Accelerator Position Sensor 2 (G185): Signal too High
P1634 - 35-00 - -
17581 - Angle Sensor 2 for Throttle Actuator (G188) Signal too High
P1173 - 35-00 - -
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
17705 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
P1297 - 35-00 - -
Readiness: 0110 1101

Address 03 -------------------------------------------------------
Controller: 1C0 907 379 E
Component: ESP FRONT MK60 0104
Coding: 0019970
Shop #: WSC 06435
1 Fault Found:
01314 - Engine Control Module
013 - Check DTC Memory


I've done a bit of googling and it seems that it could be one of my o2 Sensors , The throttle body sensors, The throttle pedal sensor or the ECU.

I've also tried re aligning the throttle body.

If the car is cold and i start it up it seems to run ok (the accelerator pedal still doesn't work) while the choke is on but as soon as it fall back down on the revs, they start pulsing again.

Has anyone on here had this happen to them ?

 

[Broken Byzan]

throttle body for the first 3, and possible boost leak for the other

 

[A3 T]

throttle body for the first 3

Thanks for the reply


That's what i thought at first from the codes given, but on other forums and the ross tech site they point more at the o2 sensor and the throttle pedal sensor.


Am i right in thinking that if i take the plug off the throttle body and put a multimeter on the plug while getting someone to put their foot down on the accelerator pedal, the voltage should go up on the multimeter?

 

[A3 T]

Update.....


I have now replaced the throttle pedal the the throttle body and the o2 sensors but the problem still remains.


I've manage to realign the throttle body with vagcom but all that has done is settle the revs.


The car now runs (although a little bit lumpy) but nothing changes if i put my foot down on the pedal.

When i clear the fault code these ones instantly come back:




18039 - Accelerator Position Sensor (G79): Signal too High
P1631 - 35-00 - -

18042 - Accelerator Position Sensor 2 (G185): Signal too High
P1634 - 35-00 - -

17581 - Angle Sensor 2 for Throttle Actuator (G188) Signal too High
P1173 - 35-00 - -

17976 - Throttle Actuator (J338): Mechanical Failure
P1568 - 35-00 - -

Address 03 -------------------------------------------------------
Controller: 1C0 907 379 E
Component: ESP FRONT MK60 0104
Coding: 0019970
Shop #: WSC 06435
1 Fault Found:

01314 - Engine Control Module
013 - Check DTC Memory

Any ideas guys as I'm out of them

 

[Broken Byzan]

you changed the throttle pot on the acc pedal and the throttle body and problems still exists?

You checked wiring? only other thing I guess could be water ingress into ecu plug

 

[A3 T]

It looking like it could be the ECU mate :-(

Every thread I've read with the same symptoms as mine end up being that the lambda cable has grounded on the exhaust and shorted out the driver on the ECU.


We had the car up on the ramp today and all the wires look ok so were a bit lost now.


Any ideas ?

 

[aragorn]

I've certainly heard of lambda heater/wiring failures causing throttle issues!

Your original scan also had codes for the lambda.

Be worth trying another ECU, but make ****** sure the lambda wiring is ok, so you dont kill the new one!

 

[A3 T]

I've certainly heard of lambda heater/wiring failures causing throttle issues!

Your original scan also had codes for the lambda.

Be worth trying another ECU, but make ****** sure the lambda wiring is ok, so you dont kill the new one!

That's what I'm worried about mate.

I don't want to spend out on another ecu only to have it blow on me the second i plug it in.

We checked the wires and they didn't look like they had melted on the exhaust...etc but maybe they have shorted internally?

I was going to just changed the o2 sensors just to be safe but It could even be that something else has shorted and blown it, I'm just running out of ideas where else to look.

 

[aragorn]

replace the probe and check the wiring for shorts with a multimeter.

 

[A3 T]

Bit of an update.....


Had someone do some tests on all the electrics and they run some earths to the ecu and the throttle pedal and everything is working.

Something must have burned out an earth component in the ecu but his wires have bypassed it.

I'm still going to change the lambda sensors as i think their a bit iffy. but now i have a bit of time to find out how to use vag can commander to recode an ecu.

 

[A3 T]

I've certainly heard of lambda heater/wiring failures causing throttle issues!

Your original scan also had codes for the lambda.

Be worth trying another ECU, but make ****** sure the lambda wiring is ok, so you dont kill the new one!

When you've heard of the sensors frying the ecu, where have you heard them failing?

I've hear that the wires touch the exhaust and shorting it out but they are never clear what part of the wiring come in contact with it.