[1.6 FSI] - Angle Sensor 2 for Throttle Actuator (G188) Implausible Signal

Evripidis

Member
Hi all,

While driving yesterday in a mountainous area and in a sharp bend all 3 lights ASR, EPC and ABS came up along with an exclamation mark on the DIS.

I was expecting this to be a wheel bearing/abs sensor fault but VCDS came up with the G188 throttle body variable resistor. The fault will go away but will come back up no matter what the driving conditions are.

Work done the day before this had happened:
1. Oil change.
2. Fit new wheel arch liner (driver's side).
3. Tighten the wiper motor bolts.

I quickly rechecked the connectors etc. and there is nothing amiss. I will be taking the throttle body apart and check the resistor tracks inside.

Before I take out the offending part, is this something that people have experience with?

All searches on the forum result in wheel speed sensor issues and not the G188.

Evros
 

PlasticMac

Member
Hi all,

While driving yesterday in a mountainous area and in a sharp bend all 3 lights ASR, EPC and ABS came up along with an exclamation mark on the DIS.

I was expecting this to be a wheel bearing/abs sensor fault but VCDS came up with the G188 throttle body variable resistor. The fault will go away but will come back up no matter what the driving conditions are.

Work done the day before this had happened:
1. Oil change.
2. Fit new wheel arch liner (driver's side).
3. Tighten the wiper motor bolts.

I quickly rechecked the connectors etc. and there is nothing amiss. I will be taking the throttle body apart and check the resistor tracks inside.

Before I take out the offending part, is this something that people have experience with?

All searches on the forum result in wheel speed sensor issues and not the G188.

Evros
You've probably done this already but here's the Rosstech info:
Mac.
 

Andrew

A2OC Donor
Something in here might provide inspiration...


[The team that wrote Google Translate should get knighthoods.]

Andy
 

PlasticMac

Member
Something in here might provide inspiration...


[The team that wrote Google Translate should get knighthoods.]

Andy
That looks like a good place to start. How did you come across that thread?
Mac.
 

Evripidis

Member
Hi guys,

Andy and Mac, hope you are doing all right.

I will drop the link in the translator and read up.

In the meanwhile I have done the following:

1. Measured the voltage at the connector pins. Checks out.
2. Taken the TB out and found out that the wiper terminals that make contact with the resistive "angle sensor" did not look right. I used a magnifying glass and still could not see a thing! I put i tunder the microscope that I use for SMT soldering and found out that the terminals are actually made up from sets of very thin strands ultrasonically welded on the tabs. Most of them had gone on top of one another. I've straightened them out, cleaned up everything with IPA and put it back together.
3. Of course I found some coolant leaks but they were minor.
4. Performed a TB adaptation.
5. Drove 20km, did not turn up but this is not conclusive so I will report back.

I have taken apart 3 different types of these from various makes. They all suffer from the same, wiper-type resistive "angle" sensor arrangement. An encoder would be much more reliable but the TB would probably cost 1500 GBP new or something.

Lets see how this one goes. I am still trying to adapt to the somewhat quieter cabin after refitting the arch liner and tightening up the wiper motor. It's the little things.
 

Andrew

A2OC Donor
That looks like a good place to start. How did you come across that thread?
Mac.
I asked Google, 'Audi A2 FSI G188'.

Using Google Chrome with the translator built in it makes a huge difference, right click, pick 'translate to English' and the whole thread is now in English, wonderful.

Andy
 
Last edited:

PlasticMac

Member
I asked Google, 'Audi A2 FS G188'.

Using Google Chrome with the translator built in it makes a huge difference, right click, pick 'translate to English' and the whole thread is now in English, wonderful.

Andy
Yes, it's clever stuff. I read the link that way too.
@Evripidis do you have Google Translate installed?
Mac.
 

Evripidis

Member
Yes, it's clever stuff. I read the link that way too.
@Evripidis do you have Google Translate installed?
Mac.

I read the post. The OP appears to have replaced the throttle body and that cured their issue. I've done two 20km trips till now and has not come back up. So maybe this is the culprit !!? Lets see!
 

Evripidis

Member
Nope. It came back up again!!!

Anyone knows where the wires run from the tb to the ecu maybe? Power and ground also?
 

PlasticMac

Member
Can't help with the location and route, but here's the throttle body connections.
Mac.
Screenshot 2022-11-15 09.57.33.png
 

Evripidis

Member
Thanks Mac. This will save me some time as I haven't got access at the moment. It appears that I have to chase the continuity of those down the the ECU something I hate doing.
 

Evripidis

Member
Well, I checked the wiring from the T.B to the ECU. I get a constant 1.5 Ohms all across without any variability when shaking the loom around.

I've taken the T.B out again for further investigation. The wires are pretty tiny so I may have missed something last time.
 

Evripidis

Member
OK , took everything out again. Cleaned up every wire and contact. All resistance values check out. Bent the wipers slightly to achieve (hopefully) a better chance of contact.

Could this be attributed to the ECU if not the T.B? There is nothing else in between the two.
 

PlasticMac

Member
OK , took everything out again. Cleaned up every wire and contact. All resistance values check out. Bent the wipers slightly to achieve (hopefully) a better chance of contact.

Could this be attributed to the ECU if not the T.B? There is nothing else in between the two.
Have you checked/cleaned the pins at the ECU end?
Mac.
 

Evripidis

Member
Hi Mac. Sure did.

This being intermittent leads me to believe either a dry joint on the inside or simply the T.B wiper tracks have worn out having lasted 180k miles. I've seen similar T.Bs last twice as long if I am honest.

EDIT: dry joint in the ECU.
 

Evripidis

Member
Hi all,

I keep clearing the fault and it keeps coming up at random intervals.

Does anyone know of any suitable t.b replacements from other vag cars? There is not a chance in hell that I can source one locally and quickly. I live in an mountainous area and the limp mode can prove dangerous.
 

Evripidis

Member
Hi all,

I am after your opinions on this one.

The fault remains intermittent with varying degrees of severity. I have not been able to find a correlation of it appearing and the driving habits or conditions.

I have triple-checked connections and connectors.

Today I plugged it in and the second G187 sensor had also come up. Cleared it all and done an adaptation of the t.b and it finished successfully. I then kept pressing on the gas pedal on/off many times and at some point the fault came up again. I tried to recalibrate with the fault on and it would not. I cleared the fault, recalibrated, drove 5 miles and it came back up again.

Are these the telltales of the t.b having gone kaput?

Evros
 
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