Sharan 2.0 ADY > No spark & mystery voltage in sensor wires to ECU ?

[Dan Stobbart]

1. Thanks to all who make this site work and contribute... it's saved much wear and tear on my credit cards over the years!

2. Current Crisis ......
1997 2.0 petrol ADY Sharan manual.
3 weeks ago it stalled at traffic lights and hasn’t started or produced a spark since.
New coil > new Crank Sensor >, new coolant temp sender, tested ECU and fuel pump relays > both transmit current when loaded, replaced Hall sender (apparently this was pointless). Checked earths, checked fuses.
Crank sensor activates injectors when I wave screwdriver in front of it BUT doesn’t produce spark at coil.
When I spin distributor to activate Cam/ Hall sender there is no spark at coil.
Injectors AND Throttle position valve can be activated via the middle (signal)pin from the Crank and Cam sensors.

But for some reason there is 9v in the middle pin of the connector to BOTH the Crank sensor and the Cam sensor.
The middle pin of the connector to the Knock sensor has 3.5v. (the outer pins of each of these 3 connectors have 12v and earth).
I thought the middle pin was meant to take a signal FROM the sensor TO the ecu?
Any thoughts will be gratefully recieved !

[Dan Stobbart]

I've seen numerous mentions by Crasher that ECU is the least likely item to fail..... but ..... The mystery 9v in the middle pin to the Crank Sensor and the Cam Sensor varies according to battery voltage. (it was 9v when the battery was getting run down , now I've recharged battery to 13.5v > the mystery voltage now reads 12.5v. It's the same in BOTH the Cam Sensor and Crank Sensor middle pins. (i.e middle pin in the 3 pin connector that brings power to the sensor , earths it, and takes a signal from sensor to the ECU)

Wiring diagrams for ADY engines suggest that they don't share a common connection on the ECU and from my rummaging under the bonnet > they don't seem to have a common cabling route to the ECU for a short circuit to affect both Cam and Crank signal wires. (they may well come close together deep under the dashboard but surely an odd coincidence for both of them to get a short circuit at the same time ?). Does this suggest a fault in the ECU ?

[robin_bga]

I've seen numerous mentions by Crasher that ECU is the least likely item to fail..... but ..... The mystery 9v in the middle pin to the Crank Sensor and the Cam Sensor varies according to battery voltage. (it was 9v when the battery was getting run down , now I've recharged battery to 13.5v > the mystery voltage now reads 12.5v. It's the same in BOTH the Cam Sensor and Crank Sensor middle pins. (i.e middle pin in the 3 pin connector that brings power to the sensor , earths it, and takes a signal from sensor to the ECU)

Wiring diagrams for ADY engines suggest that they don't share a common connection on the ECU and from my rummaging under the bonnet > they don't seem to have a common cabling route to the ECU for a short circuit to affect both Cam and Crank signal wires. (they may well come close together deep under the dashboard but surely an odd coincidence for both of them to get a short circuit at the same time ?). Does this suggest a fault in the ECU ?
Hi, I think it's high time you got yo self a new ECU n have it adapted to the immobilizer.
Cheers

VW Bora V5, AGZ, 99, 5speed Manual Tranny.