My Octavia II VRS TDI wasn't starting the other day so i checked the usual things then managed to get a hold of 2 diagnostic machines which both came back with error code 12995, crankshaft/rpm sensor G28. Tested the old sensor, it was fine but replaced it anyway.

 

It wasn't the sensor itself at fault so i'm tracing back the wiring back, it goes to one large loom that splits off in 2 directions, 1 to a connector in the engine bay that's clearly visible at the front right. I checked the wiring of the connector and it doesn't have the G28 sensor wiring.

 

I'm unsure of where the second branch of the loom goes as it runs underneath the batter compartment.

 

Anyone know where it terminates to before I start stripping down more of my engine bay to track the G28 wiring?

 

 

ENGINE CODE: BMN

TRANSMISSION: JMA

Edited 16 August, 201312 yr by EuanVRS

The wires go direct to the ECU (60-pin connector) with no intermediate connections.

G28 Pin-1 -> ECU Pin-42 black/red +ve feed

G28 Pin-2 -> ECU Pin-58 lilac S

G28 Pin-3 -> ECU Pin-57 brown/blue -

The wires go direct to the ECU (60-pin connector) with no intermediate connections.

G28 Pin-1 -> ECU Pin-42 black/red +ve feed

G28 Pin-2 -> ECU Pin-58 lilac S

G28 Pin-3 -> ECU Pin-57 brown/blue -

 

What sort of readings should I be getting if I test the pins in the G28 sensor while it's connected to the ECU?

you cant measure wihile its conected. How many V do you have on pin 1 on the wiring plug (the mother plug)??

From my knowledge, for a crankshaft sensor to test you use a multimeter set on resistance (ohm), put the sensor in hot water in check if the Ohm is increasing, but I dont know the values limitation on skoda.

You need to check for continuity and short circuits with both ends disconnected.

The resistance test was dropped on the Mk2 because it was unreliable. On the Mk1, it was somewhere between 1K and 1.5K (can't remember the exact range). No need for hot water.