AFAIK they are not the same. The Voltage Retention Unit is part of the Stop/Start system. I believe early Citroen systems used a massive capacitor (>8F) to hold power and then turn the alternator and its linked belt to turn and start to the engine. This system did not use the car's conventional starter motor. As well check your pressure sensors which are common motives of this sort of problem on the Citroen C4 Picasso. Throttle body problem: Although generally found on gasoline engines, the throttle body can be the trigger of an Citroen C4 Picasso not holding idle, try to take a look at it. To find more tips on the Citroen C4 Picasso, take a look at 1 Start motor engages but the engine doesn’t turn. Assuming your battery is healthy and fully charged, if you turn the key only to be greeted by the clunk of the starter engaging but the motor doesn’t turn, it can mean a number of things. The simplest cause of this sort of fault is a loose or corroded electrical connection. Starter Motor Citroen C4 LA LC B7 engine DV6DTED DV6C 1.6L Turbo Diesel 06-15 AU $231.00 Starter Motor for Citroen C4 Picasso engine DW10BTED4 2.0L Diesel 05-10 AUTO Examine the battery of your Citroen C4 Picasso. In most cases, a deceased or decreasing battery is without question the main reason of no-start. You might has left lights on or various other electronic equipment just like the radio and your battery’s life is dead. To be certain that the electric battery of your vehicle is flawed, generally See how the starter motor works inside below. The starter motor is powered by the car's main 12-volt battery. To turn over the engine, the starter motor requires very high electric current, which means the battery has to have sufficient power. If the battery is discharged, the lights in a car might work, but it won't have enough power (current Re: Xsara Picasso Starter / alternator change Hahahaha! Post by wheeler » Tue Apr 20, 2021 5:06 pm It could be worse, you could have the older shape Mercedes A class where the engine needs to be removed to change the starter motor Starter motor possible problem. I drove into the xcountry, no problem, did shopping and then my 2009 citroen picasso xsara suddenly wouldn’t start. Nothing just a click. So I thought starter motor or battery. Battery unlikely as I went for long drive the day before. When key removed the battery warning light stayed on (it went after 10 GPf9A7.