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Omega Help Area => Omega General Help => Topic started by: Kate on 31 March 2014, 20:55:15

Title: ABS and TC lights sometimes on sometimes off
Post by: Kate on 31 March 2014, 20:55:15
Moved to Cornwall yesterday. About half way there, while the cruise control was engaged, the abs and tc lights came on. The cruise control went off and the speedo went to zero. After about 30 miles the lights went out and the speedo started working again. ::)

Since then the lights are sometimes on, sometimes off.

Just had a used abs ecu fitted recently.

Any idea what the fault might be?

Thanks very much. :y
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: wiliferus on 31 March 2014, 21:00:20
I'm very much a Mig noob, but my guess would be a wheel speed sensor to knock out all those three things.

I'm sure some who knows a lot more will be along shortly... :y
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: 05omegav6 on 31 March 2014, 21:16:22
Sounds like the new ecu isn't far behind the old one :'(

If you still have the old one, send it away to be fixed sharpish :y
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Andy B on 31 March 2014, 21:16:55
....

Just had a used abs ecu fitted recently.

Any idea what the fault might be?

Thanks very much. :y

I'd say you need to be looking out for another ABS ECU  :(
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: 05omegav6 on 31 March 2014, 21:17:30
....

Just had a used abs ecu fitted recently.

Any idea what the fault might be?

Thanks very much. :y

I'd say you need to be looking out for another ABS ECU  :(
MTF Mr B ;D
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Andy B on 31 March 2014, 21:19:59
....

Just had a used abs ecu fitted recently.

Any idea what the fault might be?

Thanks very much. :y

I'd say you need to be looking out for another ABS ECU  :(
MTF Mr B ;D

That's over my head ......  ???
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: terry paget on 31 March 2014, 21:20:51
I had a similar fault some years ago. I changed ABS ECUs several times, fault persisted. It turned out to be rear right hand reluctor ring split and wandering about on the half shaft, in and out of alignment with the sensor.Worth a look. I cured it by gluing it in place with Araldite. I have pics if you think it likely. 
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Toledodude1973 on 31 March 2014, 21:30:31
Terry can you please put pics up , just for understanding thanks :y
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Andy B on 31 March 2014, 21:35:53
Terry can you please put pics up , just for understanding thanks :y

On the drive shaft ie from diff to rear wheel, there's a castellated ring .... that's the reluctor ring that the ABS sensors look at  :y
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: 05omegav6 on 31 March 2014, 21:37:11
....

Just had a used abs ecu fitted recently.

Any idea what the fault might be?

Thanks very much. :y
I'd say you need to be looking out for another ABS ECU  :(
MTF Mr B ;D

That's over my head ......  ???
Not rude or obscure... simply Must Type Faster ;D
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Kate on 31 March 2014, 21:38:43
I had a similar fault some years ago. I changed ABS ECUs several times, fault persisted. It turned out to be rear right hand reluctor ring split and wandering about on the half shaft, in and out of alignment with the sensor.Worth a look. I cured it by gluing it in place with Araldite. I have pics if you think it likely.

Yes pics would be really helpful, thanks. :y
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Andy B on 31 March 2014, 21:42:59
....

Just had a used abs ecu fitted recently.

Any idea what the fault might be?

Thanks very much. :y
I'd say you need to be looking out for another ABS ECU  :(
MTF Mr B ;D

That's over my head ......  ???
Not rude or obscure... simply Must Type Faster ;D

Doh!  ;D ;D ;D (33 secs faster it seems  ;D)
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Toledodude1973 on 31 March 2014, 21:52:37
i know the ring you mean now thanks, always learning with Omegas :)
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: dbug on 31 March 2014, 23:44:56
Was it a recon or 2nd hand abs ecu you fitted Kate?
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Andy B on 31 March 2014, 23:53:21
i know the ring you mean now thanks, always learning with Omegas :)

The reluctors - both front & back) are basically the same on her Smart, as they were on my Senators (never ventured under the Merc yet  :o) ) An exception was my C reg MKI Carlton, that used a single sensor that looked at the teeth on diff's crown wheel
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: henryd on 01 April 2014, 00:05:00
i know the ring you mean now thanks, always learning with Omegas :)

The reluctors - both front & back) are basically the same on her Smart, as they were on my Senators (never ventured under the Merc yet  :o) ) An exception was my C reg MKI Carlton, that used a single sensor that looked at the teeth on diff's crown wheel

A lot of cars these days use a magnetic covering on the wheel bearing seal as a reluctor :y
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Kate on 01 April 2014, 19:07:12
It was a second hand abs ecu that was fitted.

Will this be a big repair job?
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Entwood on 01 April 2014, 19:39:42
It was a second hand abs ecu that was fitted.

Will this be a big repair job?

Same size as the last one .. :(  Any second hand ECU runs the risk of the same failure as the first (and in your case - the second :( )

It is for that reason that I suggested getting yours repaired .. you then know where you stand with it .. 2 places do the job ..

ecutesting and bba-reman ....   bba-reman were £130 with a 1 year warranty, but that was 5 years back so price has probably changed....
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: terry paget on 01 April 2014, 22:06:28
Here are pics.https://www.dropbox.com/s/ag6b8t7teuhtxq1/ABS%20RELUCTOR%20RINGS%2020%25.jpg?m= (https://www.dropbox.com/s/ag6b8t7teuhtxq1/ABS%20RELUCTOR%20RINGS%2020%25.jpg?m=)
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: terry paget on 01 April 2014, 22:20:33
Sorry, pics failed. Have has to switch from Firefox to internet explorer to avoid pest of a Trojan. Will try again.
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Entwood on 01 April 2014, 22:22:41
HTH

(https://dl.dropbox.com/s/ag6b8t7teuhtxq1/ABS%20RELUCTOR%20RINGS%2020%25.jpg)

:)
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Kate on 02 April 2014, 09:39:58
Thanks for that. :y

Is there a guide for this job?
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Andy B on 02 April 2014, 11:13:05
Thanks for that. :y

Is there a guide for this job?

yes  ;)
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Andy B on 02 April 2014, 11:13:54
seek ........................ and thou shall find  ::)

http://www.omegaowners.com/forum/index.php?topic=90627.0
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: terry paget on 02 April 2014, 14:05:59
https://www.dropbox.com/s/ag6b8t7teuhtxq1/ABS%20RELUCTOR%20RINGS%2020%25.jpg (https://www.dropbox.com/s/ag6b8t7teuhtxq1/ABS%20RELUCTOR%20RINGS%2020%25.jpg)
https://www.dropbox.com/s/286s6h2n1fazzkq/RELUCTOR%20RING%20CRACK.JPG (https://www.dropbox.com/s/286s6h2n1fazzkq/RELUCTOR%20RING%20CRACK.JPG)
https://www.dropbox.com/s/mami3ko109lqtfl/DRIVE%20SHAFT%20W.CRACK%2020%25.JPG (https://www.dropbox.com/s/mami3ko109lqtfl/DRIVE%20SHAFT%20W.CRACK%2020%25.JPG)
Here are pics. One of the diff from below; you may note that the right hand ring (shiny one) is further out from diff than left hand.
One shows the half shaft removed at later date, you may glimse the crack in reluctor ring.
One shows the crack in close up.
Sorry about the delay.
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Entwood on 02 April 2014, 15:31:50
Terry ...  HTH :)

(https://dl.dropbox.com/s/ag6b8t7teuhtxq1/ABS%20RELUCTOR%20RINGS%2020%25.jpg)

(https://dl.dropbox.com/s/286s6h2n1fazzkq/RELUCTOR%20RING%20CRACK.JPG)

(https://dl.dropbox.com/s/mami3ko109lqtfl/DRIVE%20SHAFT%20W.CRACK%2020%25.JPG)
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: henryd on 02 April 2014, 17:01:14
It was a second hand abs ecu that was fitted.

Will this be a big repair job?

Same size as the last one .. :(  Any second hand ECU runs the risk of the same failure as the first (and in your case - the second :( )

It is for that reason that I suggested getting yours repaired .. you then know where you stand with it .. 2 places do the job ..

ecutesting and bba-reman ....   bba-reman were £130 with a 1 year warranty, but that was 5 years back so price has probably changed....

I think I would be getting the codes off it before getting the spanners out,it could just be something else ::)
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Kevin Wood on 02 April 2014, 18:52:59
I think I would be getting the codes off it before getting the spanners out,it could just be something else ::)

Yep, there's not much you can tell about ABS sensors by looking, unless it's something obvious like the reluctor ring missing. You can't often get the sensors off intact, so best to leave them be until diagnosed failed.

A chat with a tech 2 will establish what's going wrong, as if the ECU has failed, it's normally impossible to connect to them. Other problems leave fault codes, so easily tracked to the offending sensor.

I have to say, if it takes out the speedometer, it's normally an ECU failure. :'( If it loses one wheel sensor, it can still work out the speed using the remaining 3.
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: terry paget on 02 April 2014, 19:25:42
I think I would be getting the codes off it before getting the spanners out,it could just be something else ::)

Yep, there's not much you can tell about ABS sensors by looking, unless it's something obvious like the reluctor ring missing. You can't often get the sensors off intact, so best to leave them be until diagnosed failed.

A chat with a tech 2 will establish what's going wrong, as if the ECU has failed, it's normally impossible to connect to them. Other problems leave fault codes, so easily tracked to the offending sensor.

I have to say, if it takes out the speedometer, it's normally an ECU failure. :'( If it loses one wheel sensor, it can still work out the speed using the remaining 3.
On OE03EWW I had ABS and TC lights coming on, and lost speedo reading. I changed the ABS ECU three times, fault was nor cured. Only when I tracked it down to RH rear eluctor ring moving about did I cure the fault. Above car takes speed and distance information from rear RH sensor, and no other. I suspect all manuals are the same. On a 4 pot Omega driven by son Jonny an alarming ABS fault developed, ABS kicking in on dry roads. To make the car useable I cut the wire from RH rear sensor. Big mistake, speedo also failed. I repaired Rh rear sensor cable, cut LH rear sensor cable, and the speedo returned and the brakes worked simple - no ABS but otherwise fine.
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: 05omegav6 on 02 April 2014, 20:35:08
Terry I would suggest that had more to do with plod wiring rather than Vauxhall...

Mine had the TC disabled, and in service had a switch for disabling the ABS for collision investigation purposes.

Worth noting that TVP routinely disabled the TC switch on their Omegas.
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: terry paget on 02 April 2014, 22:20:49
Yes, Al, I used to know that. Malc Pearce told me to take out the TC switch, and behind it I would find the TVP modification. I think standard Vauxhall was TC normally active, but pressing the TC switch de-activated it, light came on, until switch pressed again or engine restart. I think TVP mod was TC always on.

I do not this affects my analysis of the ABS and speed/distance info coming from the RH rear ABS sensor, indeed as it also did on Jonny's 2.0 manual.
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: 05omegav6 on 02 April 2014, 22:24:10
Yup, they essentially bypassed the switch :y
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: Kate on 05 April 2014, 21:13:12
Thanks for all the advice. :y

The lights have stayed off all week apart from once when I was doing 70. It seems that the lights only come on when going fast.

Does this narrow the problem down at all?

Title: Re: ABS and TC lights sometimes on sometimes off
Post by: omega squared on 06 April 2014, 21:12:36
Thanks for all the advice. :y

The lights have stayed off all week apart from once when I was doing 70. It seems that the lights only come on when going fast.

Does this narrow the problem down at all?

when the ABS ECU starts to fail its an intermitant fault and then eventually you have no speedo of all the time, ABS sensors can be similar, fingers crossed your 2nd hand ECU is ok, if not (as previously stated) send it to ECU Testing Ltd for a refubd £130 or BBA £180 both plus vat.
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: terry paget on 07 April 2014, 05:30:32
Thanks for all the advice. :y

The lights have stayed off all week apart from once when I was doing 70. It seems that the lights only come on when going fast.

Does this narrow the problem down at all?
Mine was the same, occurred mainly on motorways at high speed. Makes sense, with a split eluctor ring at high speed, rapid halfshaft turning, centrifugal force would spread the ring and encourage wandering. Sorry about the tiny pics, you really could not see how the left and right rings differed, could you? Will try again.
Title: Re: ABS and TC lights sometimes on sometimes off
Post by: terry paget on 16 April 2014, 08:35:56
Better pics here.
https://www.dropbox.com/s/3evyr79n9ecnawj/absRINGcrack40%25.JPG (https://www.dropbox.com/s/3evyr79n9ecnawj/absRINGcrack40%25.JPG)
https://www.dropbox.com/s/me62825ilxj14th/ABSringsRHdisplaced40%25.jpg (https://www.dropbox.com/s/me62825ilxj14th/ABSringsRHdisplaced40%25.jpg)