Ds3 stop-start fault

[Derekjones]

Hi all I have a ds3 1.6 airdream e-hdi 110hp 62reg with a fault code of 1A9CH/6812 undocumented, it appears with engine fault service and stop-start disabled, I have replaced the battery like for like but still no success any ideas

[GiveMeABreak]

You're missing part of the fault code - so not sure what code reader you're using, but if it's P1A9C, then this will relate to the energy accumulator. You probably forget that your vehicle doesn't rely only on the main vehicle battery for Stop Start. This model could be fitted with a high capacity ultra capacitor / energy accumulator and converter unit. These are hidden under the front left wheel arch and are used for storing energy for the older stop start systems.

Over time the capacitor needs replacing as it ends service life (which it's now done 13 years service). Be advised these need special equipment to discharge them before handling / replacement as you can get a hell of a belt from them. Best to have it done by your dealer / specialist.

[Derekjones]

Thanks for the help, can the stop-start function be linked out on the ecu as to remove the fault and clear the service light

[GiveMeABreak]

Not as far as I'm aware, as it's integrated into the charging circuit and other systems, so may cause other faults.