Aygo IG -ecu power issue

[Russ8922]

Any help would be appreciated is there a common fault on these fuse board I could fix etc.

My daughters Aygo 63 reg,  

Power steering died P-S light on ,ABS and EML.

In obd diagnostic it's showing low voltage on IG, loss of communication to brake control module etc due to low voltage.

Circuit 1-3 on internal fuse box left of steering wheel 

1) ECU IG CIRCUIT

2) BACKUP CIRCUIT 

3)WIPERS

if all fuses removed the socket show normal voltage 12.8 or around 14v if started

However with all 3 fuses in the voltage accross all drops to around 5v.

If any one of the 3 fuses only is inserted voltage drops to around 7v with the exception of ECU IG CIRCUIT which brings voltage to 5-6v on its own.

Rest of fuse circuits showing normal voltage it's just these 3 fuses circuits it seems.

Also if just circuit 3 fuse is insert and wipers are switched to off position the fuse board makes a buzz noise but when wiper set to on position they don't operate but buzzing stops.

[flash22]

mk1 aygo ?,

Are the Battery terminals clean and tight ?

Go get the Battery tested, the voltage maybe ok, but the Battery capacity maybe low, the first few cold snaps can take out a battery, not just the cold but the higher current draw due to defrost, heating and lights being used As the current rises the voltage will drop anything below 9v and the ecu-b, ecu and other modules will not be happy

 

[mrfixer]

It would certainly pay to have your Battery tested.  However there are also other checks you can make.

With the engine running check that you have 13.6 - 14.5V at the Battery terminals.  Now do your voltage measurements at those fuses again.  If the voltages are still low with the fuses inserted then that suggests to me that there is high resistance somewhere in the feed to those fuses. When current is being drawn by those circuits the voltage drops because of the resistance (Ohm's law). I don't have access to a circuit diagram but I suggest tracing back to whatever is feeding those fuses (a IG relay, main fuse?)..

[flash22]

1. 2 and 3 are fed from the IG relay (likely the buzzing you can hear)

control comes from the ignition switch via fuse IG1  (7.5a)

Power is fed from fuse AM1 (40a)

Aygo's have a habit of knocking relays loose

I must have been down this road before as I have location Pic arrowed

A bit of a mare to get at as it is buried under the dash

Borrowed from another thread

Note, the 2 grey relays on the right

Ignore the red circle, those relays are located in the white block near A pillar up to 2012 

After 2012 the IG relay will be in R/B No.5 (just above the red circle) IG will be the LH relay

 

 

[flash22]

My mistake yours it after 2012 the IG relay will be in R/B No.5

above post correct to show this