The Importance of Power Steering Oil Pressure Switches

Cambiare explains the workings of their newly introduced power steering oil pressure switches and the importance of these on the power steering system.

While power steering oil pressure switches are not new technology, it is a fairly new product line to be introduced to the aftermarket.

Core Function

The power steering oil pressure switch works very much like the engine oil pressure switch. Their core function is to activate the warning light on the dashboard when oil pressure is low. However, the information gathered from a power steering oil pressure switch can be used for a number of purposes.

In some applications, the power steering oil pressure switch also feeds information about demand on the power steering system to the vehicle’s engine ECU. This allows it to manage engine speed during low-speed parking manoeuvres. An increase in demand on the power steering system means increased load on the engine. As these sort of manoeuvres usually occur when the engine speed is low, the engine ECU will need to increase the engine speed to compensate for these extra loads or the engine will stall. This is why the power steering pressure switch is an important part of the system.

Steering Demands

It can also be used to identify power steering faults and display this to the driver via the Engine Management Light (EML). As these switches are working in the power steering system, the pressure demands are much greater than the engine oil pressure switches.

The power steering oil pressure switch has a diaphragm that either opens or closes the connection depending on whether the switch is Normally Open (NO) or Normally Closed (NC). When the fluid pressure is high enough to overcome the diaphragm spring pressure, it will make or break the electrical contact thus, signaling steering demands to the ECU.

Switch Failure

The diaphragm and switch components are subjected to constant flexing and heat. Over time, this can cause the pressure switch to fail. If this happens, the power steering demand information will not be relayed to the engine ECU. Therefore, the extra loads exerted by the steering system cannot be compensated for.

A failing power steering oil pressure switch can present a number of symptoms. Here are a few common ones:

  • Engine revs dipping when the power steering is operated
  • Engine stalls during low-speed steering/parking manoeuvres
  • Engine Management Light (EML) coming on

Newly Introduced

Cambiare heavily invests in research and development as they recognise the importance of introducing products that are relevant to the demands of the current aftermarket. This is reflected with Cambiare’s four power steering oil pressure switches that covers over 1.2 million vehicles within the UK car parc.

Since the release of this range late last year, these four part numbers have been received very well by customers, swiftly moving up the pareto. In turn, they are firmly on their way to becoming established part numbers in Cambiare’s engine management range. Cambiare also expects to introduce more additions to this range as new numbers are introduced in the aftermarket.

Cambiare’s power steering oil pressure switches are backed by a 2-year/30,000-mile warranty. They are catalogued on the Cambiare website (, the F:Drive and MAM Autocat. For more information, speak to your local Cambiare or FPS representative.


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