Ds3 2016 1.6 diesel no start

[Castro12]

Have the above model and upon changing the battery it has refused to start, upon turning the key the starter motor sounds like it wants to engage but it doesn't turn the flywheel. Battery voltage is fine being a new battery and was tested, removed the starter motor and the Bendix shoots out and spins fine, there's power to the starter and bridging the motor it turns the engine over fine, tapping the starter with it mounted to the car hasn't done anything either and it will not start. Obd reader connected reveals a fault with the turbo which not prevent it from starting, the only other thing illuminated on the dash is the STOP sign in red is there a way to turn this off? I presume this is something with the car that prevents it from starting so what does it mean? I don't have a coolant problem or any abs faults on the car as the manual refers to this being associated with the stop light.All fuses check out fine as well both in the cabin and engine compartment.

[BarneyRubble]

Start with the BSI Reset / Battery Disconnection / Reconnection procedure here:

viewtopic.php?p=601679#p601679

See if that clears the problem.

Once that's done, check the voltage on the trigger wire to the starter (the thin wire to the starter motor). When somebody turns the key, what voltage are you seeing? It should be 12V. If it's <9V you may have corrosion, partially broken wire or a faulty BSI (Built-In Systems Interface=fusebox plus motherboard).

Also, what happens if you connect a jump lead from the negative terminal to the engine block? Does it start then?
If so you may have a corroded/missing earth strap to the engine (gearbox).

One other possible problem might be the clutch switch if it's a manual. "If the vehicle fails to start despite the clutch pedal being fully depressed, the Clutch Switch may be malfunctioning, preventing the necessary signal to the ECU for engine engagement." You can test the switch or bridge it temporarily to see if the switch is at fault - might even be just naff contacts that a squirt of contact cleaner might clean up. I can personally recommend Halfords Electrical contact cleaner. https://www.carsparesltd.com/product/fu ... OL20817SEN

Good luck!

[Castro12]

Hi, thanks for your reply I've tried the bsi reset several times and this failed to resolve the problem. Am receiving 12 volts on the trigger wire to the starter and there's no corrosion, I've also tried a good ground to the chassis and engine block and nothing has happened. The clutch fuse has been checked several times and depressing the clutch doesn't start the car either, I will however take a look at the clutch switch as I haven't checked that. Thanks

[RichardW]

Wind back a bit... What was it doing before you changed the battery? Are you sure you reconnected everything at the battery?

[Castro12]

The car ran perfectly fine, the battery was disconnected for a couple of days and removed simply till a new one arrived, everything has gone back as it should and now this has happened.