hmm, do I really need to disconnect the battery? ABS ecu

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Post Reply
HDI Dave
Posts: 334
Joined: 14 May 2009, 11:20
Location: Bradford,Yorkshire
My Cars:
x 3

hmm, do I really need to disconnect the battery? ABS ecu

Post by HDI Dave »

Evenin all,

Finally going to sort my osf abs sensor out tomorrow,my mot man will be pleased..(he's passed it twice,but he wasn't best charmed last time!).

Haynes says disconnect the battery negative lead.

Why? Will it spike something or other? (yes,electrics aint my forte').

I can't remember now how I tested the sensors,ie,battery on or off..I'm sure it was on..else how would you get a reading?

Front left 907 ohms
Rear left 905 ohms
Front right zilch, 0
Rear right 904 ohms.

And my major beef is I've just got my radio set up nicely,after years on the wrong settings etc :lol: so I really don't want to mess it up again..

I'm sure having the battery on won't bother it myself, I just don't want to damage the abs ecu for such a simple lead off.

darned newfangled ecu's,sensors etc..there'll be a sensor/warning light/bing bing bing noise telling you to take a p!$$ one of these days :lol:

Cheers, Dave.
1999 Xantia LX 2.0 HDI 110 Rusteration project...
User avatar
Xaccers
Posts: 7654
Joined: 07 Feb 2007, 23:46
Location: Milling around Milton Keynes
My Cars:
x 184

Post by Xaccers »

I've never disconnected the battery to replace a ABS sensor.
1.9TD+ SX Xantia Estate (Cassy) running on 100% veg
1.9TD SX Xantia Hatchback (Jenny) running on 100% veg for sale
Laguna II 2.0dCi Privilege (Monty)

DIY sphere tool
User avatar
VertVega
Posts: 1178
Joined: 01 Nov 2008, 19:39
Location: Province nordique de l'Union européenne
My Cars:
x 13

Re: hmm, do I really need to disconnect the battery? ABS ec

Post by VertVega »

HDI Dave wrote:... Haynes says disconnect the battery negative lead. ...
Haynes is wrong on this also, as in many others :roll: :wink:

As Xac said above, you don't have to disconnect the battery for ABS sensor measurement or replacement.
Autodata also confirms the same.
Last edited by VertVega on 10 May 2011, 19:49, edited 1 time in total.
C5 II 2.0i 16V - 2005 - Estate - 103KW - EW10A - Petrol - Manual
HDI Dave
Posts: 334
Joined: 14 May 2009, 11:20
Location: Bradford,Yorkshire
My Cars:
x 3

Post by HDI Dave »

Ok, cheers guys, that'll do for me 8-)
1999 Xantia LX 2.0 HDI 110 Rusteration project...
citronut
Posts: 10937
Joined: 29 Apr 2005, 00:46
Location: United Kingdom east sussex
My Cars:
x 92

Post by citronut »

even though the battery curent does not come into play whilst testing continuaty/resistance on ABS sensors,

if useing an OHM meter or you could blow your meter up,


regards malcolm
HDI Dave
Posts: 334
Joined: 14 May 2009, 11:20
Location: Bradford,Yorkshire
My Cars:
x 3

Post by HDI Dave »

Funny thing you should say that Malcolm!

My trusty multi/pocket meter, (Gunsons standard fag packet sized jobby), wouldn't read ohms today..zilch,zero..neither would my back up meter,although the (meter) battery was knackered..bit strange though, measured fine before?!!..So I had to measure it with the arrow setting..or the hFE one,can't remember which one now, but it gave me a reading of 1.2 on em all.(before, my OSF sensor read zero,so I checked it plugged in before I refitted it properly*).

Good job fathers' day is approaching..(ooh look,machine mart catalogue has crazily fallen open on such a page!)
..everyone hates buying me tools..but it's a 1000 times better than a jumper..or slippers :lol:

* well I didn't refit it 'properly'
Jeez, if the front sensors are easy (I think I've read), I'd hate to do a rear one!
12 years of crud,original routing,what a complete pain in the ass :evil:
even when the sun was burning..blue sky..it kept raining on and off,whilst the bonnet was up with the abs ecu's private parts splayed wide open nakedly..

I re routed it, still to the strut mountings, but then around the back and just under the track control arm,so the connector is sitting on the wishbone,helluva lot easier to get to.

Quick test drive...abs light's on..oh for fgss....
100 yards, light's off :D (ecu have to 'learn' it's there?).

Put wheel back on,(after noticing the tyre's scrubbed on the inside tread,and there's been a 'clunk' for a while..) and a rock from side to side clearly shows the bottom ball joint's paggered :roll:
oh well,best sort it now, mot's due next month.

What's the price from GSF,or dare I say it Citroen? If crazy £ I'm looking at this:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT

oh and here's me sensor,5 days to arrive from Germany :)
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT
1999 Xantia LX 2.0 HDI 110 Rusteration project...
User avatar
Xaccers
Posts: 7654
Joined: 07 Feb 2007, 23:46
Location: Milling around Milton Keynes
My Cars:
x 184

Post by Xaccers »

citronut wrote:even though the battery curent does not come into play whilst testing continuaty/resistance on ABS sensors,

if useing an OHM meter or you could blow your meter up,


regards malcolm
How? The sensor is disconnected.
1.9TD+ SX Xantia Estate (Cassy) running on 100% veg
1.9TD SX Xantia Hatchback (Jenny) running on 100% veg for sale
Laguna II 2.0dCi Privilege (Monty)

DIY sphere tool
citronut
Posts: 10937
Joined: 29 Apr 2005, 00:46
Location: United Kingdom east sussex
My Cars:
x 92

Post by citronut »

no no i know Xac, what i was trying to realay is you should not use an ohm meter on anything with current up it :wink: ,


also if the battery in you meter is dead it wont work on the ohm setting,


regards malcolm
User avatar
Xaccers
Posts: 7654
Joined: 07 Feb 2007, 23:46
Location: Milling around Milton Keynes
My Cars:
x 184

Post by Xaccers »

citronut wrote:no no i know Xac, what i was trying to realay is you should not use an ohm meter on anything with current up it :wink: ,


also if the battery in you meter is dead it wont work on the ohm setting,


regards malcolm

Aaah that makes sense!
1.9TD+ SX Xantia Estate (Cassy) running on 100% veg
1.9TD SX Xantia Hatchback (Jenny) running on 100% veg for sale
Laguna II 2.0dCi Privilege (Monty)

DIY sphere tool
Post Reply