Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: terry paget on 25 April 2013, 20:31:30
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1999 T reg 2 litre petrol manual saloon
Having changed the ABS ECU to cure the ABS light on fault, muddled up my ECUs so changed it again, the fault is still there. I conclude the fault is elsewhere. Sensors? Cogged wheels? Cables? Please advise most likely.
Incidentally, changing the ABS ECU was not the heroic endeavour described in the maintenance guide. I am sure the experts on this forum do it a better way. I did it on a 2 litre this time, but the same technique works on the V6.
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Suspect from your previous post the 2 ecus not the same (part nos ;) )
Suggest getting a known working one with same part no as original and trying that. :y
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Thanks for your advice.
Both ECUs were from 2 litre petrol manual Omegas, one a T reg, one a V reg. The V reg was working OK when scrapped. The numbers were not identical, but similar. On fitting each worked normally initially (ABS light on on turning on ignition, then going after 4 seconds, staying off on engine start, staying off on turning car in drive, then on driving out of drive and turning left down the hill light came on. On neither occasion did I see the light come on, but both events were amazingly similar.
How would I obtain an ECU with a more similar part number? Which part of the number is critical? Most of the numbers were the same. Both pump units were DF models.
I have been here before! IN 2007 my 3.2 ex police Omega behaved similarly. I bought a used ECU for a V6 manual from Steve Brown for £200, fitted it, and the fault remained. I took Steve's ECU off, sent it back for refund. and sent my ECU to ecutesting for repair. They said it was all right, sent it back, charged me a fee. I then replaced my old ECU, concluding fault lay elsewhere.
Swopped all the wheel sensors, no change. Then I checked the cogged wheels. The rear o/s cogged wheel was loose on the half shaft end and was sliding in and out of line with the sensor. I glued it in place with Araldite. Fault cured.
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T reg 2 litre petrol manual saloon
This car had ABS light coming on, so today I changed the ABS ECU for one off a similar car I scrapped last year. I had put the new ECU on the pump block when I thought it would be good to get a photograph, so I removed it again. I took a photograph, then realised that I had two identical ECUs sitting on the bench. I did not know which was which. I gambled that the ECU with a little power steering fluid on it was the one I had removed, so I installed the other one.
Went for a test drive, and the ABS light came on. Bother.
I removed the ECU again. The spare ECU had come off a V reg car so presumably was the younger. The labels read as follows: The one I had installed read BOSCH and a bar code; on right 04527
on bottom 965560 0 273 205
The other (left on the bench) read BOSCH and a bar code, 43330 on right
and 871113 0 273 285
I suppose the fault could lie elsewhere, a sensor, cable or a cogged wheel.
Can someone tell me which of these ECUs is the older? Any ideas where the fault might lie? I have known sensors fail, cables fray (on front wheels) and the cogged wheels move about (back only). Would a Tech2 reading help?
Different part nos ;)
Critical part is 0 273 205 or 0 273 285
:y
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Thanks to dbug and apologies to all. On checking my photographs, both numbers end 0 273 205. Bosch put a diagonal line across their zeros, making it look like an 8. The 8 commencing the other number is quite different.
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It sounds like you need the codes read to determine if it's a problem elsewhere. Assuming the new ECU is correctly configured, the fact that it threw a fault after a little driving makes me think it's a wheel sensor / reluctor ring issue.
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ABS ECU problems are "usually" accompanied by speedo problems, steering problems, TC problems ... as they are all linked via the ECU .... as you are only experiencing the ABS bits it is quite possible the problem is outside the ECU as KW says.
I would suggest a visit to one of the Tech2 boffins on here who know what they are doing and can correctly diagnose the problem rather than changing bits "on spec" ... :(
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Thanks to Kevin and Entwood. I was caught out by a moving elector ring in the past, but at a quick glance at my rear pair they looked all right. I don't think the front rings can go anywhere, can they? I suspect a frayed front cable or failed sensor, so I will check for continuity next.Will report back.
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All four sensors have continuity, resistance about 700 ohms. Disappointing
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ABS ECU problems are "usually" accompanied by speedo problems, steering problems, TC problems ... as they are all linked via the ECU .... as you are only experiencing the ABS bits it is quite possible the problem is outside the ECU as KW says.
I would suggest a visit to one of the Tech2 boffins on here who know what they are doing and can correctly diagnose the problem rather than changing bits "on spec" ... :(
My 2.2 had the same symptoms as the OP, behaved as it should for a short time, then ABS light would come on, no other problems with anything else. IIRC the fault code said the ECU was at fault. Mr DTM kindly helped me out at Newent one year to help me change it, but it turned out mine had more actuators than the replacement.....so the original was stuck back on......never did get to the bottom of the cause.
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ABS ECU problems are "usually" accompanied by speedo problems, steering problems, TC problems ... as they are all linked via the ECU .... as you are only experiencing the ABS bits it is quite possible the problem is outside the ECU as KW says.
I would suggest a visit to one of the Tech2 boffins on here who know what they are doing and can correctly diagnose the problem rather than changing bits "on spec" ... :(
I don't think the 2.0 has traction control or servotronic power steering so not conclusive IMO :-\
A visit to a Tech2 guru would be my next course of action (assuming that there are no visible signs of damage to reluctor rings, sensors or cables.)
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Thanks to all for advice. Visual inspection of reluctor rings and cables reveals no obvious faults. Alarming tale from Taxi Driver about fault code saying faulty ECU but ECU change not curing fault. Too many actuators (sensors?) I do not understand. Was the ECU from an automatic?
Andy H is correct. Car has no traction control or servotronic power steering. Speedo works OK.
Are there members near me (BA3 2LP Bath Bristol area) with Tech2s who would help? What is the procedure? There is a local Vx dealer who might help, but I hardly know him.
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Thanks to all for advice. Visual inspection of reluctor rings and cables reveals no obvious faults. Alarming tale from Taxi Driver about fault code saying faulty ECU but ECU change not curing fault. Too many actuators (sensors?) I do not understand. Was the ECU from an automatic?
Andy H is correct. Car has no traction control or servotronic power steering. Speedo works OK.
Are there members near me (BA3 2LP Bath Bristol area) with Tech2s who would help? What is the procedure? There is a local Vx dealer who might help, but I hardly know him.
My 2.2 was an auto.....the ecu replacement was from another member on here....who said it would fit a 2.2.....i didnt know there were differences on abs ecu's.....however when my abs ecu was taken off it had six actuators inside it.....the replacement only had four.....so clearly wasnt going to fit.
Nearest tech2 to you is Mr TheBoy or whatever he's called these days.....in Brackley :y
If you wanna try the Bath Vx dealer.....ive had good dealings with them regarding a LPG Veccy C ......they originally changed the vapouriser for several hundred pounds less than other vx dealers were quoting.....then i got an air leak on the vacuum to the vap....which i fixed myself....but the lpg ecu needed reseting (it is an adaptive ecu, and had maxed itself out trying to cope with the air leak....hence its settings were all over the place after i cured the air leak and wouldnt run on lpg). The service manager said he was too embarrassed to charge the min labour charge for just resetting the ecu (£45) and charged me £20.....carnt say fairer than that......but its been a few years since ive been there so carnt vouch for what its like now :-\
Edit...PS I would have gone to see Jaimie (The Boy) but a tech2 carnt read/reset a factory fit lpg ecu.
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Or if you can wait until 1st/2nd of September theres always the Newent meet......not far from you.....and bound to be a tech2 or 2 there :y
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Thanks Taxi Driver. For some reason automatics take speed information from gearbox output shaft, not rear wheel sensor, so they have different ABS ECU setup.
This car is my son Jonny's transport. I have it back for its MOT test. He lives in Chippenham. I live in Midsomer Norton, south of Bath. Every Friday I travel to Didcot for golf and tennis; my trade club registration is at Bellingers, Grove, near Wantage, so your country. One of my tennis chums has his Rover 75 service in Swindon.However Downside Motors, Chilcompton, is 3 miles from me, and they have a Tech2 and have helped me in the past.
My worry now is that you had faulty ECU diagnosed, but a new ECU did not cure it. Is the fault still with you?
Must check where Newent and Brackley are.
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Thanks Taxi Driver. For some reason automatics take speed information from gearbox output shaft, not rear wheel sensor, so they have different ABS ECU setup.
This car is my son Jonny's transport. I have it back for its MOT test. He lives in Chippenham. I live in Midsomer Norton, south of Bath. Every Friday I travel to Didcot for golf and tennis; my trade club registration is at Bellingers, Grove, near Wantage, so your country. One of my tennis chums has his Rover 75 service in Swindon.However Downside Motors, Chilcompton, is 3 miles from me, and they have a Tech2 and have helped me in the past.
My worry now is that you had faulty ECU diagnosed, but a new ECU did not cure it. Is the fault still with you?
Must check where Newent and Brackley are.
No....it was diagnosed as faulty ecu....but it was never changed....tried to....but replacement wasnt going to fit.....i havent got the 2.2 anymore.....sold it when it was 6 years old with 150k on it and a long list of problems ::)
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Fellow OOF members,
one more curiosity in this ABS saga.
In the past I have had ABS problems.
In 1996 on a Citroen CX I had an intermittent ABS light coming on for a year, finally traced to a frayed front sensor lead. In 2007 on an Omega 3.2 I had intermittent light coming on, changing ECUs was no help, traced to wandering rear reluctor ring; cured by gluing it in place. IN 2011, Omega 2.5 manual estate, light came on intermittently and with increasing frequency, cured by sending ECU to ecutesting for repair.
In above cases, on ignition switch on ABS light would come on, then go off after 4 seconds. On this car (1999 2 litre manual petrol saloon) the light never came on. Did not worry me, passed 3 MOTs. Reading press this April I learn that bulbs are checked, so I put in a bulb (bulb had been absent). Bulb stayed on. Oh dear.
I had a spare ECU from a scrapped car, so I popped it in. Turned on ignition, ABS light came on, after 4 seconds it went off. Joy. Took for test drive, ABS light come on. Bother. Thereafter ABS bulb stayed on.
Thought I might have mixed up ECUs, so replaced original ECU. Turned on ignition, ABS came on, after 4 seconds went off. Confused. Went for test drive, ABS light on again. And stayed on.
I do not understand why removing and replacing ECU should give it a brief burst of good behaviour. Could it be removing it from battery power? I have just nipped out, removed negative battery lead, and replaced it. ABS still constantly on. I do not understand it at all.
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The ABS ECU uses a host of tiny aluminium wires (about the size of a human hair) to connect the pcb in the ECU to the multiway connector.
The common mode of failure is for the aluminium wires to fracture. My guess is that unplugging & replugging the ECU caused movement in the pins of the multiway connector sufficient to temporarily make a good electrical contact.
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Thanks Andy H. That makes a lot of sense. I recall a comment on the Catera site along those lines; it said repair can be achieved with aluminium conducting paint. I suppose what ecutesting does for £100 is repair the broken wire. I have noticed on the ECUs they return they have obviously opened the casing and repaired something. Can I do that? Has anybody in the OOF done that?
Are they aluminium wires? I cannot solder those. I hope they are tinned copper, or lacquered copper. Please advise.
.
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Repair of the wires needs to be done by bonding on specialised equipment. As mentioned they are as thin (or thinner) than a human hair,so normal methods such as soldering wont work.Its something that I could possibly get done at work,but the problem is that they are encased in some sort of gel,which needs removing first.
I dont know the process for removing this,so cant find out if repair is a possibilty at work until I find out how to do that. :(
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Thanks Albitz. that's bad news. The wires to the plug are substantial enough, I hoped the wires from socket to pcb would be similar. I suppose the wretched thing is mass produced by a clever machine, then the pcb to socket section is dunked in some soft setting compound to insulate and support the wires.
I have repaired pcb's in the past by spotting cracked soldered joints and resoldering them. I have repaired breaks in the printed circuits of Omega instrument panels by soldering in light wires where they have burned out. But this sounds beyond me. I wonder if I opened it up and probed around between socket pins and solder points on the pcb whether I could find the failed connection and slip in a light wire. Has no OOF member done that? Replacing central locking microswitches sounds delicate work, but members refer to it as a simple task, like a wheel change.
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Thanks Albitz. that's bad news. The wires to the plug are substantial enough, I hoped the wires from socket to pcb would be similar. I suppose the wretched thing is mass produced by a clever machine, then the pcb to socket section is dunked in some soft setting compound to insulate and support the wires.
I have repaired pcb's in the past by spotting cracked soldered joints and resoldering them. I have repaired breaks in the printed circuits of Omega instrument panels by soldering in light wires where they have burned out. But this sounds beyond me. I wonder if I opened it up and probed around between socket pins and solder points on the pcb whether I could find the failed connection and slip in a light wire. Has no OOF member done that? Replacing central locking microswitches sounds delicate work, but members refer to it as a simple task, like a wheel change.
From the sounds of it, you would need to use kit that i used many moons ago, when repairing circuit boards....to start with a microscope to actually see what you were doing.....and then a soldering iron small enough.....i used to use a £500 soldering iron which used to heat the tip, smaller than a needle using ultrasonics.....oh and solder paste.
For what i remember the tips of the iron used to burn out every few days.....at iirc £40 a pop to replace them.
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Thanks Albitz. that's bad news. The wires to the plug are substantial enough, I hoped the wires from socket to pcb would be similar. I suppose the wretched thing is mass produced by a clever machine, then the pcb to socket section is dunked in some soft setting compound to insulate and support the wires.
I have repaired pcb's in the past by spotting cracked soldered joints and resoldering them. I have repaired breaks in the printed circuits of Omega instrument panels by soldering in light wires where they have burned out. But this sounds beyond me. I wonder if I opened it up and probed around between socket pins and solder points on the pcb whether I could find the failed connection and slip in a light wire. Has no OOF member done that? Replacing central locking microswitches sounds delicate work, but members refer to it as a simple task, like a wheel change.
From the sounds of it, you would need to use kit that i used many moons ago, when repairing circuit boards....to start with a microscope to actually see what you were doing.....and then a soldering iron small enough.....i used to use a £500 soldering iron which used to heat the tip, smaller than a needle using ultrasonics.....oh and solder paste.
For what i remember the tips of the iron used to burn out every few days.....at iirc £40 a pop to replace them.
The last time anyone used BBA Reman I think it cost them around £100 and the part was returned working and guaranteed in less than a week.
I consider myself to be quite proficient at soldering (I started helping my father to solder fiddly little components as a six year old) but I am realistic about my (in)ability to solder aluminium or to remove the goo so I wouldn't hesitate to send my ABS ECU to BBA if it fails.
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Thanks Albitz. that's bad news. The wires to the plug are substantial enough, I hoped the wires from socket to pcb would be similar. I suppose the wretched thing is mass produced by a clever machine, then the pcb to socket section is dunked in some soft setting compound to insulate and support the wires.
I have repaired pcb's in the past by spotting cracked soldered joints and resoldering them. I have repaired breaks in the printed circuits of Omega instrument panels by soldering in light wires where they have burned out. But this sounds beyond me. I wonder if I opened it up and probed around between socket pins and solder points on the pcb whether I could find the failed connection and slip in a light wire. Has no OOF member done that? Replacing central locking microswitches sounds delicate work, but members refer to it as a simple task, like a wheel change.
From the sounds of it, you would need to use kit that i used many moons ago, when repairing circuit boards....to start with a microscope to actually see what you were doing.....and then a soldering iron small enough.....i used to use a £500 soldering iron which used to heat the tip, smaller than a needle using ultrasonics.....oh and solder paste.
For what i remember the tips of the iron used to burn out every few days.....at iirc £40 a pop to replace them.
The last time anyone used BBA Reman I think it cost them around £100 and the part was returned working and guaranteed in less than a week.
I consider myself to be quite proficient at soldering (I started helping my father to solder fiddly little components as a six year old) but I am realistic about my (in)ability to solder aluminium or to remove the goo so I wouldn't hesitate to send my ABS ECU to BBA if it fails.
I couldnt solder the stuff now i used to repair back then.....looking through a microscope.....using a 'needle' type iron, rock steady hands.....and also chatting to a fellow worker at the same time ;D ;D
I also used diagnose what was wrong with the pcb......using a pc with test harness connected to the pcb to send signals to the pcb and using a scope to diagnose where the signal wasnt getting thro......doubt if i could that either now ;D ;D