ABS problem Ibiza 2007. Rear left sensor

[awes]

I have a problem that drives me nuts.
I have searched several forums and followed many threads without getting closer.

My ABS warning light is on.
Scanning for code it say Rear Left sensor (290).
Replaced sensor.
Checked cables that are visible - no wear from what I can see.
WD40 in connector both down at the wheel and up at the pump
Delete the error code.
*As soon as I turn on ignition the error code comes on again.
I see several threads about replaced the trigger wheel down at the wheel hub, but as my fault comes on without even moving the car I guess it is a connection problem or similar somewhere.

Are there any known places where the cables get into problems? Or are there more connectors somewhere in between the ABS pump and the wheel?

Thanks for your help
Anders
Spånga, Sweden

[zollaf]

so , first job is to get a multi meter. disconnect the abs sensor and find the other ends of the wires where they enter the ecu. do a continuity check on both wires. alternatively, use little jumper cables to connect the sensor directly to the ecu, ruling out the 2 wires.
incidentally, you are right about the trigger wheel. when you start the car the abs does a self check. if the light stays on, it can not be the trigger wheel as this would only show once the car is moving.

[awes]

so , first job is to get a multi meter. disconnect the abs sensor and find the other ends of the wires where they enter the ecu. do a continuity check on both wires. alternatively, use little jumper cables to connect the sensor directly to the ecu, ruling out the 2 wires.
incidentally, you are right about the trigger wheel. when you start the car the abs does a self check. if the light stays on, it can not be the trigger wheel as this would only show once the car is moving.

Thanks for the suggestion. Any idea where I can find schematics for electricity so I can identify what goes where up at the ABS pump.
BTW, you say "connected to the ECU". I thought the sensors where connected directly to the ABS pump and not via the ECU?

[zollaf]

the abs ecu may be integrated into the pump. no diagram, you need to pull the plug, find the colours and trace them back to the wheel in question, or find a diagram. usually quicker just to trace them.