2012 Hyundai IX35 Pricing and Specs

My information suggests the crank-angle sensor for this engine is located on the rear of the cylinder block (near where the engine joins the transmission) near the oil filter housing. It’s usually hidden by a small heat shield and requires that and a 10mm bolt to be removed to remove the sensor.

Access to the wiring harness is usually from above, but the sensor itself is most easily removed from underneath the car after removing any relevant plastic shielding.

What you need to do is work backwards and check every connection and wiring plug that is anywhere near where you were working. A single unplugged (or even loose) sensor, connection or fitting can absolutely sideline a modern, electronically controlled engine.

You may also find you’ve damaged a sensor in the process of cleaning it (they’re pretty sensitive things) so a scan of the car may reveal that.

Also, was the cleaning process initiated by an existing problem that made you think the sensors needed cleaning? Cleaning an already dud sensor rarely brings it back to life.

A poor earth is often the cause of this sort of misbehaviour and it’s a good place to start looking. Check the earthing points in the engine bay and around the area where the tail-lights are earthed in the cargo area.

You might need to lift some carpet or trim pieces, but when you find the earth points, make sure they’re tight and clean and not covered in corrosion. Don’t forget to check the tightness and cleanliness of the battery terminals, too.

Beyond that, these symptoms point to a problem with the car’s body computer which controls all these functions and many more.

When this computer starts to die, all sorts of weird and random flaws can occur. But try this first: Disconnect the battery of the car and let it sit overnight. Reconnect it next morning and keep a close eye on what happens. Sometimes this simple trick will reboot the body computer and normal service will be resumed. Best of all it’s free.