Power steering failure

[Natasha_Young]

Citroen DS3 2010 - After not starting my car for 1 week, it started fine however the power steering light and ESP light was on and the power steering wasn't working. After a few restarts, the lights went off and the car drove normally. Now every time I start the car, the lights are on and the power steering doesn't work. I have checked the battery and alternator, both are fine. I've also charged the car for 48 hours incase the battery voltage was just slightly below where it needed to be. Still no luck. The only way I can get the lights to clear is by starting the car and revving the engine for 1 minute and then restarting the car. The car then drives like normal.
Code reader picked up fault code U1121: Absence of communication with the electric power steering no signal and U1321: Operation of the electric power steering.
Has anyone experienced anything like this or knows what might be the problem?

[GiveMeABreak]

I've deleted your duplicate thread on the DS Forum as having 2 identical posts will confuse and duplicate answers.

It may yet still be a weak battery - if it's over 5 years old then it's probably at the limit of its duty cycle to be honest - in other words it may not be operating at full capacity as over time it will not be able to hold as much charge as it did at new.

With modern cars and all the electronics, there is a greater demand on the battery - there is the electric power steering and all the ECUs, plus systems that continue to operate for a while after the ignition is switched off - and of course there is the alarm system being powered etc.

So I suggest you test that the alternator is operating correctly and charging the battery at about 14.7 V with the engine running which you can test with a multimeter. Check the battery terminal wiring is ok and not corroded, then consider getting a new battery of the correct capacity.

[Natasha_Young]

I’ve had Halfords check the battery and alternator and they said both were ok. However the test they did on both was just after I’d driven the car once and by that point, the lights had gone off the dash. Do you still think it’s worth trying a new battery?

[Paul-R]

Is it still on the original battery? Ten years is extremely good going if it is.

[Natasha_Young]

I’ve had the car 5 years and in that time I haven’t replaced the battery. Not sure if it was replaced prior to that though.

[Paul-R]

There will be a date code somewhere. Can you post a photo of the top of the battery and we may be able to identify it?

[JohnD]

Yes - I've experienced this after the car has stood for a few days. The engine has managed to start but power steering hasn't worked. After leaving the engine at a fast idle for a few minutes, after switching off and restarting, power steering was back to normal. A new battery was called for.

[Natasha_Young]

The only code I can see on the battery E3CO861810054p60.

JohnD- did you also have the ESP light on until the restart?

[Paul-R]

It's usually shorter than that. Something like 0410 or 04/10. It may be printed on or it may be embossed into the plastic casing itself.

[Natasha_Young]

250610 which I'm guessing means it's never been replaced!

[Natasha_Young]

[Paul-R]

Took me ages to find it on the photo but, yes, it looks like it's a ten year old battery.

Time for replacement?

[Natasha_Young]

No luck with the new battery. Any other ideas?

[Paul-R]

Could I ask what battery you had fitted? Is a good name? Do you know what capacity the battery has?

You may need to let the system adjust to having a new battery. Is it any better yet?

[Natasha_Young]

It was just a test battery. I’m trying a new alternator next Wednesday because that was showing as slightly low, although it shouldn’t have been so low to have caused the power steering failure but it could also be faulty in one way or another.
The car is still working fine as long as I rev the engine after first starting (power steering and ESP lights on dashboard) and then restart it. That way the lights go off the dash and the steering comes back. Very odd...what do you think?