Engine speed sensor/ new problem

[aussiebob]

Hi all,
I had an engine speed sensor fault on my 1.6ltr Mk4 according to vagcom. Replaced it today, cleared the fault, and then, whammo, the car now won't start at all. It was very bad at starting before I replaced the sensor but now won't even try to start. I ran vagcom again and it now has a new fault:

Tuesday, 06 March 2012, 16:12:04.
Control Module Part Number: 06A 906 019 BQ
  Component and/or Version: 1.6l 2V/R4 SIMOS HS3120
           Software Coding: 00031
            Work Shop Code: WSC 00028
                      VCID: 73995CCF52BB
1 Fault Found:
00668 -  Supply Voltage Terminal 30
        36-10 -  Open Circuit - Intermittent


I'm a serious noob when it comes to repairing cars but thought I could tackle the speed sensor, but now, I am at a loss as to what to do next, aside from go to a mechanic and get them to tdo the detective work. The car won't even try and start at all and the dash goes blank when I try to turn it over and then there is a bit of a ticking noise when I turn the ignition off.......

Any help appreciated.
Cheers.

[richw911]

Dead battery?

[aussiebob]

Hasn't been a problem up until now though?!!!!

Doesn't turn over at all since changing the speed sensor. Could that be it?

[richw911]

Hasn't been a problem up until now though?!!!!

Doesn't turn over at all since changing the speed sensor. Could that be it?

Doubt it check the earth leads and the main leads at the starter motor

[aussiebob]

Checked and can't see anything loose or not connected.......

Excuse my ingnorance but there is one single red wire coming out of the top of the block, seems to be at the throttle body, and it isn't connected to anything? The end of it is dusty and dirty though, not shiny copper so appears to not be a new thing? Connected to the fault maybe? Can't see where it is meant to end either.

The ironic thing is, if I can't find this problem I may have to put the old speed sensor back on and see if that fixes it.......

[aussiebob]

Just tried it again, and the car is trying to start but only for a split second and then just nothing.......AAARRRRGGGHHH, there i was thinking I could change the sensor and now its FUBARED!!!

[richw911]

Just tried it again, and the car is trying to start but only for a split second and then just nothing.......AAARRRRGGGHHH, there i was thinking I could change the sensor and now its FUBARED!!!

Loose / Broken lead somewhere 

[richw911]

Have you checked the fuse box on top of the battery is properly secure?

[aussiebob]

Hey guys,

Would you believe, it was the battery. Seems it had a dodgy cell and by running Vagcom a couple of times without starting after just stuffed it. Replaced the battery and she started first time and seems to be running sweet. Many thanks for the suggestions.

Aussiebob

[richw911]

Hey guys,

Would you believe, it was the battery. Seems it had a dodgy cell and by running Vagcom a couple of times without starting after just stuffed it. Replaced the battery and she started first time and seems to be running sweet. Many thanks for the suggestions.

Aussiebob

Glad you sorted it