Audi Cabriolet 2.6 Stalling after 2-3 seconds - Page 2

Jaco Mostert · 18-04-20, 04:37 PM

I found the immobilizer...

Pin 2 - Coil to ignition (signal)
Pin 3 - Coil to ignition (screen)
Pin 6 - Warning lamp
Pin 9 - ECU (W-Wire)
Pin 10 - Diagnostic Wire
Pin 11 - Earth
Pin 12 - 12V Power

The other pins are not used. Pin 1, 6, 7 and 12 are indicated on the plug and box.

I am now 99% certain it is the cause of my problem. Disconnecting the immobilizer and bridging pin 9 and 10 in the plug enables VCDS to read the engine module, which had a code for "17978 - Engine Start Blocked by Immobilizer"

I opened the immobilizer box and plugged it back in while testing for continuity with a multimeter. The immobilizer has pin 9 and 10 bridged when the car is off. As soon as I turn the key the continuity between these pins is broken.

I have not tested the wires to the ignition switch, but it seems the car recognizes the key since the light for the immobilizer goes out. This with the fact that I can't read the immobilizer in VCDS makes me think the immobilizer is bad. Now I need to replace it or somehow bypass it.

18-04-20, 04:37 PM	#11
Jaco Mostert Grown up member Join Date: Dec 2013 Location: South-Africa, Hartbeespoort Posts: 49	I found the immobilizer... Pin 2 - Coil to ignition (signal) Pin 3 - Coil to ignition (screen) Pin 6 - Warning lamp Pin 9 - ECU (W-Wire) Pin 10 - Diagnostic Wire Pin 11 - Earth Pin 12 - 12V Power The other pins are not used. Pin 1, 6, 7 and 12 are indicated on the plug and box. I am now 99% certain it is the cause of my problem. Disconnecting the immobilizer and bridging pin 9 and 10 in the plug enables VCDS to read the engine module, which had a code for "17978 - Engine Start Blocked by Immobilizer" I opened the immobilizer box and plugged it back in while testing for continuity with a multimeter. The immobilizer has pin 9 and 10 bridged when the car is off. As soon as I turn the key the continuity between these pins is broken. I have not tested the wires to the ignition switch, but it seems the car recognizes the key since the light for the immobilizer goes out. This with the fact that I can't read the immobilizer in VCDS makes me think the immobilizer is bad. Now I need to replace it or somehow bypass it.