Omega Owners Forum
Omega Help Area => Omega Electrical and Audio Help => Topic started by: Ralph M on 16 September 2009, 18:36:21
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Can anyone help me with my 2002 Omega 3.2 litre MV6?
Speedo has stopped and power steering is no longer speed sensitive, but ABS and traction control work and there are no warning lights. Vauxhall say the speed sensor is providing its normal output and their tech 2 diagnostic unit can communicate with the ABS ecu and says there is a No:- 21 trouble code - No vehicle speed signal - servotronic. They also say the speed output cable from ABS ecu to engine fails a continuity test. Their solution is to install a new wiring loom for the whole car at £600 plus 20 hours labour to install it, any alternative cheaper suggestions will be gratefully received.
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From what I have read on these forums there is a good chance that the failure is actually inside the ABS ECU (between the circuit board and the connector).
I have also read that it is an absolute pig of a job to get the ABS ECU out otherwise my first suggestion would be to pull the plugs off the two ECU's and check the continuity of the wiring loom with a multimeter.
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Can anyone help me with my 2002 Omega 3.2 litre MV6?
Speedo has stopped and power steering is no longer speed sensitive, but ABS and traction control work and there are no warning lights. Vauxhall say the speed sensor is providing its normal output and their tech 2 diagnostic unit can communicate with the ABS ecu and says there is a No:- 21 trouble code - No vehicle speed signal - servotronic. They also say the speed output cable from ABS ecu to engine fails a continuity test. Their solution is to install a new wiring loom for the whole car at £600 plus 20 hours labour to install it, any alternative cheaper suggestions will be gratefully received.
On the mini-face V6 there is a relay located behind the glovebox and is red in colour, controls the servotronic system. Not sure whether you got the same :-/
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Can anyone help me with my 2002 Omega 3.2 litre MV6?
Speedo has stopped and power steering is no longer speed sensitive, but ABS and traction control work and there are no warning lights. Vauxhall say the speed sensor is providing its normal output and their tech 2 diagnostic unit can communicate with the ABS ecu and says there is a No:- 21 trouble code - No vehicle speed signal - servotronic. They also say the speed output cable from ABS ecu to engine fails a continuity test. Their solution is to install a new wiring loom for the whole car at £600 plus 20 hours labour to install it, any alternative cheaper suggestions will be gratefully received.
If you update your profile with more info, maybe someone close to you that can have a little look for you :y ABS ECU change not too difficult just a bit fiddly, which is what it sounds like to me, but with no dash lights coming up, really needs codes read. HTH
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No:- 21 trouble code - No vehicle speed signal - servotronic
Did this code come from the Servotronic or the ABS ECU? Sounds more like a servotronic error.
ABS/TC ECU failure is relatively common but a failed ECU will normally not talk to a Tech 2 so it is important that we are sure if they were able to talk to it.
IMHO, wiring loom failure is not likely, and not worth spending that sort of money on a hunch. Even if that circuit has failed (i doubt it has - the ABS ECU has stopped sending the speed signal!) I would be looking to repair the loom, not replace the whole thing.
Kevin
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BTW.. ABS ECUs can be refurbished for just over 100 quid. :y
Kevin
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Even if that circuit has failed (i doubt it has - the ABS ECU has stopped sending the speed signal!) I would be looking to repair the loom, not replace the whole thing.
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Ah! But that would involve a little thinking & working out - far easier for a vauxhall 'tech' to replace rather than repair ;) ;) ;) :y :y
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Could be abs and tc bulbs previously removed! Do they come on ok when ignition switched on?
Does sound like dodgy rear n/s sensor.
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Ralph M - where are you. We have a few people around the country with access to the same diags equipment as Vauxhall, but are more highly skilled than the monkeys in the dealers.
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Do you have cruise control and if so, does it work? It's just that it also uses the speed signal output from the ABS ECU.
If its of any help, the wire in question is red/blue that also runs to the following places:
Xenon headlight control unit
Satnav connector socket (passenger footwell behind kick panel)
If you don't have cruise then you could access the signal on the cruise connector under the bonnet. Also use the red/blue wire, it provides a switched on/off 12v signal proportional to vehicle speed @ 1004 pulses per mile. Setting a meter on 12v DC between the red/blue and ground will see the signal switch on/off/on/off as you drive along, drive faster and the rate increases,
My point here is that if you can tap into the signal somewhere and you do get the switching on/off signal then the ECU is outputting, if not then not - if you can see my logic. You could also do a continuity test, - if you get continuity from the cruise connector back to the red/blue wire on the ECU then the signal isn't leaving the ECU, if you don't get the continuity then you may have a damaged wire somewhere.
Continuity testing is ok as long as you restrict it to JUST the red/blue wire. My money is on the ECU.
HTH ........ Rob
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Can anyone help me with my 2002 Omega 3.2 litre MV6?
Speedo has stopped and power steering is no longer speed sensitive, but ABS and traction control work and there are no warning lights. Vauxhall say the speed sensor is providing its normal output and their tech 2 diagnostic unit can communicate with the ABS ecu and says there is a No:- 21 trouble code - No vehicle speed signal - servotronic. They also say the speed output cable from ABS ecu to engine fails a continuity test. Their solution is to install a new wiring loom for the whole car at £600 plus 20 hours labour to install it, any alternative cheaper suggestions will be gratefully received.
i have exactly the same prob with my 98 omega, and ive even had the abs ecu re-conned