The power steering (PAS) on my 2012 SEAT Ibiza 1.4 FR suddenly became intermittent. After a 30 mile trip and fortunately only a few miles from home I stopped to refuel but on restarting the car there was no PAS whatsoever. Testing it out on the driveway, it came and went a few more times but clearly needed to be repaired. Interestingly there were no fault codes registered in VCDS and the warning light on the dash only came on when actually moving along – otherwise it was off.
Power Steering on my Ibiza (and from the same era VW Polo and Skoda Fabia) all use an electric pump to pressurise hydraulic fluid to assist the steering.
The hydraulic pump +ve supply is permanently connected (via a fuse) to the battery (there’s no relays or anything else in the way) in my case the fuse is where the battery would be if it wasn’t located in the boot of my particular car. Hidden under the blue plastic squares (see below) are the fragile metal fuses. The first thing to check is these fuses, which I believe can bocome fractured. I removed the plastic covers to check, but that isn’t easy to do, so I’d not advise it – just use a meter.
To get access to the PAS pump and its connectors you really need to remove the bumper and wheel arch cover. The first check should be for a constant voltage at the plug marked BAT_V+ on the diagram below. There should also be a good clean Ground connection. With the ignition on you should see 12V on connector KL_15 – so check that next. Pull off the plug and test between ground and KL_15 in the plug. This voltage powers the Controller board inside the pump and may be all that’s needed to actually switch on the pump but you do need the CANBUS signals to control the speed—and maybe even start the pump? There are two types of steering system and this one is TRW – with the steering angle sensor mounted on the steering wheel and there’s nothing connected to the third connector (LWS_SGN etc)
With ignition on, check for about 2.5 volts between GND and CAN_H or CAN_L – this is a good indicatation that you have a good connection to the CANBUS which controls the pump speed. Before ordering a new pump I also put an antique scope on the CANBUS pins and saw a typical signal showing the data on the bus – very reassuring.
In the end I ordered a refurb pump from eBay and a direct swap fixed the problem.