This is my son's abused and well used Fabia. It's been an amazing little car, until he went over a cattle grid, then soon after it died, and has refused to start ever since.  Being towed home on the end of a rigid towing pole was an experience for me.

 

Charged battery: Plugged in our old OBD reader, Originally gave P1545 error, plus one for air con (but it's had this fault for ever). Splashed out on VCDS system and we get.

 

18049 - Please check DTC Memory of A/C Controller

            P1641 - 35-00 -

17851 - Potentiometer for EGR (G212)

            P1443 - 35-10 - Signal too Low - Intermittent

17952 - Angle Sensor 1 for Throttle Actuator (G187)

            P1544 - 35-10 - Signal too Large - Intermittent

17564 - Manifold Pressure Sensor (G71)

            P1156 - 35-10 - Open/Short to Ground - Intermittent

17580 - Angle Sensor 2 for Throttle Actuator (G188) Signal too Low

            P1172 - 35-10 -  - Intermittent

 

We've cleaned the throttle body and did the reset sequence (with the VCDS).  Sensors are showing as follows. This is when car is on, but obviously wont start.

 

We've noticed as well, when you press the accelerator that the butterfly on the throttle body doesn't open. But when car ignition on or do a rest it does move and chatters into place.

 

Hubby thinks the 'going over a cattle grid' is a big clue, but so far can't find any loose or broken connections.  We're considering buying a new throttle body, but conflicting opinions across the various forums we've read at some length; seem to suggest they hardly ever fail even though the huge quantity available across the internet and the usual parts suppliers suggests there is a large market for new ones.  

 

Asking for any suggestions for what else we can check?  Also can anyone suggest how we can test or prove if the throttle body is ok or dead. Found one youtube vid showing test values across various terminals, but it was for a ford one, so no idea if the same terminals would read the same on a vag one.  

 

Any help gratefully received.

 

 

 

I reckon a plug has come out that maybe wasn't fully clipped back in sometime in the past, start with the MAP sensor since there's a code for this, check the crank position sensor next since this can cause non-starting, also check the ECU multiplugs are fully pushed home.

Output tests will have one to actuate the throttle valve.

4 minutes ago, J.R. said:

Output tests will have one to actuate the throttle valve.

Is this with the vcds? I’ll have to find it. I did a test that when I pressed the pedal  , it showed increased/decreased sensor setting but the throttle body didn’t move.

Have you looked at the cabin fusebox to make sure no fuses have shaken themselves loose/out?

1 minute ago, Breezy_Pete said:

Have you looked at the cabin fusebox to make sure no fuses have shaken themselves loose/out?

We took everyone out and tested them, but I’m wondering if we should give it another go. Engine will rotate but doesn’t start. 

11 minutes ago, viragomidget said:

Is this with the vcds? I’ll have to find it. I did a test that when I pressed the pedal  , it showed increased/decreased sensor setting but the throttle body didn’t move.

Yes, output tests are what the name says, you can open the windows, test the heater fan, door locks etc etc, you can also actuate the EGR and throttle body.

 

I would also run an output test on the fuel pump as this could be another suspect for a connection being shaken up or a wire broken.

See if there's 5V at pin 1 (red/green wire) of the cam sensor connector with ignition on.

EGR, MAP sensor and cam sensor all use this 5V supply. TB also has a 5V feed to the position pots, but not sure if it's the same rail. Purple/red on pin 2 of the TB conn.

Edited 4 June, 20232 yr by Breezy_Pete

I had a coil pack go, which blew the fuse so the car would turn over but not start.  Maybe something there?

6 hours ago, jonmad said:

I had a coil pack go, which blew the fuse so the car would turn over but not start.  Maybe something there?

Thanks, we did check all the fuses. Did yours blow one of the bigger ones?

12 hours ago, viragomidget said:

Thanks, we did check all the fuses. Did yours blow one of the bigger ones?

 

I don't think it was a big one, 5A ,maybe, I can't remember exactly.  I bought a bag of them then swapped out the coils one at a time until the fuse stopped blowing.  Then replaced that coil - no more fuses blowing and the car starts again.

Cabin fuse 52 supplies all the coilpacks, a 15A blade fuse.

Fuse 35 is injectors' supply, 10A rated

Fuse 56 is an ignition switched feed to the engine ECU, 20A rated.

May as well check all of them. 

On 04/06/2023 at 21:23, J.R. said:

Output tests will have one to actuate the throttle valve.

Hi All

Another evening on the car. Did the output tests, and it does actuate the throttle body. But what was strange was when I 'ended the test', it kept going. Had to turn engine off.

We tested the pins on the throttle body plug. Pin 1: 2.8v, Pin 2, 5v, Pin 3, 10.3v, pin 4 0v (red/green wire). Pin 5 and 6 both 0v

We couldn't find the crank sensor, but tests never showed that has an error. 

We checked all the fuses again and changed a few, just to try and still same.

Engine turns over, but won't start (we are charging battery between).

The throttle body butterfly doesn't appear to move when we attempt to start it, despite pressing the throttle. 

 

Anyone any other ideas? Please?

 

 

Try a secondhand throttle body with exactly the same part number that's on yours, I reckon.

7 minutes ago, Breezy_Pete said:

Try a secondhand throttle body with exactly the same part number that's on yours, I reckon.

Hi Pete

Virago's hubby here.  Have certainly considered that, but the only second hand one on ebay looks like its spent six months under water😀 Can't help but think that it wouldn't move under the output test if it was faulty.  I'd probably prefer to go with a new one, a Lucas one is £115.  But I'd like to check the crank sensor first. Now I know where it is I'll take another look tomorrow. 

 

 

Hi, not sure what you're searching, but my info suggests you need 036133062M.

This one seems potentially like a great bargain https://www.ebay.co.uk/itm/256100509572  and seems to be plenty of others.

 

Fair play for trying to eliminate other stuff first though. 🙂

57 minutes ago, Breezy_Pete said:

Hi, not sure what you're searching, but my info suggests you need 036133062M.

This one seems potentially like a great bargain https://www.ebay.co.uk/itm/256100509572  and seems to be plenty of others.

 

Fair play for trying to eliminate other stuff first though. 🙂

Wow, not sure how my ebay searches didn't find that, must have looked a dozen times over the last week or so.  Yes thats the exact part....and we've bought it. Thanks.  Just have to wait for it to arrive now.  THANKS....

I reckon you can view the crank sensor output using "live data".

So another play this morning. Tried the new throttle body, no difference. Still can’t find or how to test the crank sensor. Found what I believe is the speedo sensor on top of the diff housing.  Think this is heading for scrap

Don't think it will have a vehicle speed sensor, does what you found look like this?

 

Crank sensor isn't far from there, on back of block looking at back face of flywheel, I think. Will try to find a good image.

 

 

Here you go, vertically below TB.

48 minutes ago, Breezy_Pete said:

Don't think it will have a vehicle speed sensor, does what you found look like this?

 

Yes, thats what I found. Looks like speed sensor to me, reading shaft rotations out to the wheel. 

 

It's a dummy sensor, pull it out of diff and you'll see. ABS wheel speed sensors do the job on your car.

Edited 11 June, 20232 yr by Breezy_Pete

Ok. Found that with a torch and mirror.  There isn’t actually a sensor there on the engine, not that you can get at. It’s obviously on the crank oil seal, bit like our old 2.0tdi Sharan was.  The bit you can see behind the flywheel is just an entry grommet for the wire. 
 

Followed the wire back across behind the engine, and theres a connector back left corner.  So I unplugged it, turned engine over, read the fault codes with my basic obd reader and got a ‘Engine speed sensor fault’. Plugged back in, erased fault codes, turned engine over again, no fault codes!!  

So I’m pretty sure the crank sensor and it’s wiring is fine.