C1956 steering angle sensor fault.

[mgallimore]

Hello. I have a C-Max 1.8 tdci.  It has a C1956 engine code fault and a warning message displays at startup "power steering malfunction".  The steering feels fine in use.

I have had the code read and cleared several times. The warning code comes back each time the engine is started after having cleared the previous error code.

I have been told by the engine diagnostics chaps that the problem is the wiring loom between the ehps pump and the steering rack sensor. I made up a new 3 wire loom which was tested for shorts and continuity before i fitted it. Still the same engine code problem. I added voltage test points on the new loom and tried to measure sensor voltages whilst the car was running. I expected to see 12v or 5v rel earth on one wire (sensor supply). I expected 0v on a second wire (the sensor ground wire). and either a variable analogue or digital output on the sensor output wire. All I measured was 0v on all three wires. I disconnected the sensor and got the same 0v on all 3 lines. Fuses F2 and F22 are ok.  This suggests to me a possible pump fault since it does not seem to be supplying the sensor voltage. I can however hear the pump running and the power steering feels normal to use.

Does anyone think I'm on the right track? Any other opinions / suggestions would be gladly received.

regards, MArk

[ges_ford]

Hi, did you get to the bottom of this issue? I seem to have an identical problem at the moment on my 2008 C-Max. Any info would be gratefully received. Thanks Graham