P0817 Reversible Alternator restarting authorisation line

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Naved
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P0817 Reversible Alternator restarting authorisation line

Post by Naved »

Hi All,

back again. I bought a second hand alternator (9815455980, IST60C032) identical to my vehicle. When placed in the Citroen C4 grand picasso 2016 I had no errors but I had not driven the vehicle just started it. A day later I have the following error after driving:

P0817 Reversible alternator restarting authorisation line
C4_P0817ErrorReverseAlt.jpg
Stop start is not working either it show that is goes into the mode with the green ECO flashup on the dials as the car comes to a stop. ECO flashes up for 3 seconds but does not turn off the engine. Is the stop start likely to be associated to this error with the reversiible alternator? Clearing the fault does not get rid of it. Is the alternator likely to be faulty or could it be the Start/stop ECU?

Stop start usually not working is down to the battery but I have a brand new battery fitted today.

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GiveMeABreak
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Re: P0817 Reversible Alternator restarting authorisation line

Post by GiveMeABreak »

Ok, so I have little info on this fault (in fact it is not a code coming up for your specific vehicle). However it can mean that there is a problem with the starter disable circuit. This can mean that starting is disabled if it is not detecting the gear selection lever being in the right position. That will disable Stop Start too if it cannot determine the gear position. So the current is not what is expected in the system. But I don't have anything further as the fault is not a code that comes up....

So maybe you'll have to bite the bullet and get the dealer to sort this one.

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Re: P0817 Reversible Alternator restarting authorisation line

Post by wheeler »

Does this car have a separate starter motor?
Was there not a bit of confusion on this one as to whether it was meant to have a reversible alternator or not?
Have you confirmed with a voltmeter that the car is now charging?

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Re: P0817 Reversible Alternator restarting authorisation line

Post by Naved »

Hi Marc,

this car has a starter motor see pic.
StarterMotor.jpg
I turned the car around today for an oil change. Also opened the passenger side wheel and arch liner to see the star stop ECUand disconnected the battery. see pic .Opened the two 10mm nuts that hold the tray tried to take off the third earth point but a standard hex would not fit so decided to open it later. Done the oil change and placed the engine cover tray back.
StartStopECU.jpg
Re connected the battery. I went to start the car and pressed the start button and I can hear a click but no cranking and now have the service light on with Engine fault and the old error reappear P1A96 Reversible alternator unknown identifier. Is there likely to be a connectivity issue between the connector and the ECU of the start stop ? The replacement alternator is identical and I did not have this error P1A96 until I moved arround the tray where the start/stop ECU was today.

In a previous instance (yesterday) I had taken the the positive terminal out and then placed it back to start the car when it was clicking and not cranking and this workaround started the car. The gear selector would be recognisable as I left it in Park mode after I turned the car into my drive. When I move the gear selector it shows the correct selected gear on the dial screen.
identifierFinal.JPG
I will not be carrying out my workaround as I have reproduced the issue. I will swap the old battery that is now fully charged to see if the car starts and check the new one for volts. Is the starter disable circuit part of the Main ECU or the start/stop ECU under the passenger wing?
Last edited by Naved on 10 Oct 2020, 18:49, edited 1 time in total.

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Re: P0817 Reversible Alternator restarting authorisation line

Post by Naved »

I decided not to change battery as I felt battery had the cranking amps needed to start the car. I removed the positive terminal and placed it back and car started. This time no engine light and no service light. Any ideas what is not initialising? I will check for the remaining errors tomorrow but think only the Reversible alternator authorisation line error will remain.