Using the Lexia I got the following readings for the voltages
1) When reading the engine ECU the voltage will read 12v
2) When reading the AL4 ECU the voltage will read 14.5 V
Voltage of 14.5 v is normal and using a voltmeter this is what is measured on the battery terminals . Does the above indicate that the engine ECU voltage it too low ? If yes will it affect its functionality , mainly the analog to digital conversion of the various sensors ? Is there a wiring scheme that I can use to track the ECU voltage feeding and find why it drops to 12V ?
Thanks
Zohar
Xantia – Voltages reading
Moderator: RichardW
-
- (Donor 2022)
- Posts: 711
- Joined: 30 Nov 2010, 07:02
- Location: Israel
- My Cars: Xantia 2.0 16V Automatic make year 2000 LHD
Citroen C4 THP Automatic make year 2009 LHD
Citroen C4 VTS 2.0 16V make year 2006 LHD - x 8
Xantia – Voltages reading
Xantia 2.0 16V Automatic make year 2000 LHD
Citroen C4 THP Automatic make year 2009 LHD
Citroen C4 VTS 2.0 16V make year 2006 LHD
Citroen C4 THP Automatic make year 2009 LHD
Citroen C4 VTS 2.0 16V make year 2006 LHD
-
- Moderating Team
- Posts: 11563
- Joined: 02 Apr 2005, 16:11
- Location: Charmouth,Dorset
- My Cars: Currently:
C5 X7 VTR + Satnav Hdi estate Silver
C5 X7 VTR + Hdi Estate 2008 Red
In the past: 3, CX td Safaris and about 7, XM td estates. Lovely cars. - x 1199
Re: Xantia – Voltages reading
I would suspect it has a voltage regulator in circuit, try it without the engine running and see if its still 12v
Peter
Peter
-
- (Donor 2022)
- Posts: 711
- Joined: 30 Nov 2010, 07:02
- Location: Israel
- My Cars: Xantia 2.0 16V Automatic make year 2000 LHD
Citroen C4 THP Automatic make year 2009 LHD
Citroen C4 VTS 2.0 16V make year 2006 LHD - x 8
Re: Xantia – Voltages reading
The voltages changes as the revs change so I guess there isn't a voltage regulator
Thanks
Zohar
Thanks
Zohar
Xantia 2.0 16V Automatic make year 2000 LHD
Citroen C4 THP Automatic make year 2009 LHD
Citroen C4 VTS 2.0 16V make year 2006 LHD
Citroen C4 THP Automatic make year 2009 LHD
Citroen C4 VTS 2.0 16V make year 2006 LHD
- myglaren
- Forum Admin Team
- Posts: 25361
- Joined: 02 Mar 2008, 13:30
- Location: Washington
- My Cars: Mazda 6
Ooops.
Previously:
2009 Honda Civic :(
C5, C5, Xantia, BX, GS, Visa.
R4, R11TXE, R14, R30TX - x 4888
Re: Xantia – Voltages reading
More likely the regulator has failed.
-
- (Donor 2022)
- Posts: 711
- Joined: 30 Nov 2010, 07:02
- Location: Israel
- My Cars: Xantia 2.0 16V Automatic make year 2000 LHD
Citroen C4 THP Automatic make year 2009 LHD
Citroen C4 VTS 2.0 16V make year 2006 LHD - x 8
Re: Xantia – Voltages reading
Is this regulator part of the engine ECU ? But if it fail how comes that the ECU still functions ?
Thanks
Thanks
Xantia 2.0 16V Automatic make year 2000 LHD
Citroen C4 THP Automatic make year 2009 LHD
Citroen C4 VTS 2.0 16V make year 2006 LHD
Citroen C4 THP Automatic make year 2009 LHD
Citroen C4 VTS 2.0 16V make year 2006 LHD
- myglaren
- Forum Admin Team
- Posts: 25361
- Joined: 02 Mar 2008, 13:30
- Location: Washington
- My Cars: Mazda 6
Ooops.
Previously:
2009 Honda Civic :(
C5, C5, Xantia, BX, GS, Visa.
R4, R11TXE, R14, R30TX - x 4888
Re: Xantia – Voltages reading
Can't answer that Zohar but if the ECU doesn't carry it's own internal regulator I imagine it will fail sooner or later if presented with varying voltages especially over 12V.