I have come across quite a number of posts on the net regarding power steering failures on the S-max, here is my sad story hopefully someone can help.

2008 UK Smax 20.0tdci Duratorque, EHPAS System (electric, hydraulic power steereing)

My S-Max steering has suddenly failed with “power steering failure” coming up on the dash. There is no assistance whatsoever.

Some more info:

• Fluid level was fine. It is however rather black.
• I have pulled the pump out and removed the electrical cover in-case the problem was a bad connection/ingress etc. No issues found. It would seem the pump is rather complex to strip further at this point.
• No blown fuses, grounds seem all good, electrical systems not showing any signs of issue.
• The battery voltage is fine @12.5v and 13.5v with the engine running so I don’t think it’s an “availability of power” issue i.e alternator.
• I did not notice any foreign bodies, metal contamination etc in the oil after draining.
• With the engine running, if I unplug then re-connect the power connector to the pump it spins up and sounds good for a couple of seconds. The steering appears to work for this very short time. The pump then starts to shake/cavitate for a second or two before stopping.
• It would be good if I knew what was causing the pump to stop.
  • Is it the pump itself, perhaps an over-pressure?
  • Pressure switch on the pump, rack or line?
  • Is it over-current perhaps?
  • Mechanical failure of pump? Sounds fine when it runs for that short while!

• Fluid level drops when the pump spins for this short time so it’s getting good fluid supply.
• I have a basic ODB code reader and is only shows one fault which comes up as “N/A”. Not of much use I guess!

Previous experience and googling tell me that It’s likely to be one of a few things:
1. Pump fault. New pump required.
2. Rack fault, valves blocked etc. Would this trip the pump out?
3. Steering angle sensor?

I guess I would just like some suggestions to help me rule out certain things. I am just a bit worried that if I put it into a local garage they will just throw very expensive parts at it until it’s fixed.

Get the eps dtcs read properly first.

Cheers,

I am booked in to read the codes and take it from there. Initial comments from some mechanics seem to point to the pump. Replacement pumps to joe public are pretty hard to find (for good reason perhaps).

There are a few 2nd hand on ebay and the like, bit of a risk since you don't know what your buying. Euro car parts sell aftermarket units from Remy and TRW. What I don't know is if these will come already set-up for the car, as far as I can gather all these pumps are very similair, but do they do all the neccasary communication with the cars systems out of the box?

I would go out on a limb and guess that they may need model specific "profiles" loaded by the ford computer. Not sure what the generic CAN/processor setup would be. (probably because i'm not a ford mechanic!!) I am however an engineer with lots of experience on control systems, hydraulic systems, PLC's, CAN bus etc.

It would seem also that Volvo use this pump in their models, would this pump work out of the box? Perhaps the units have custom firmware loaded for diffrent manufacturers. The mind boggles..

Cheers

Colin

Gave up trying to fix myself. Nightmare trying to get information from anywhere, considered a second hand pump but bit the bullet and put to a Ford garage. £700 New pump fitted. Hope that's the end of it.