Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: MonzaGSE on 05 October 2020, 17:24:47

Title: ABS light on
Post by: MonzaGSE on 05 October 2020, 17:24:47

Car is a 94 omega 2.0 manual. Suddenly the ABS light came on. Light goes out as it should when car is started, but comes on and stays on when the car starts moving. Local garage couldnt get a good reading of the codes as it was an older system they said. But the reader they had indicated a relay fault. Speedo works fine. Next step will probably be to go to Opel and get them to read the codes with tech2. Am i most likely looking at an ecu replacement?

Title: Re: ABS light on
Post by: Enceladus on 06 October 2020, 16:55:41

I would first check the sensors and their wiring Starting with the rear axle. I think they can be checked with a multimeter. Test procedure might be in Haynes. Else a Google trawl and YouTube will be useful.

Title: Re: ABS light on
Post by: TheBoy on 06 October 2020, 17:17:34

Technically, a 94 is covered by Tech1/Tech1a, not Tech 2. But as the ABS unit is the same until 97, a Tech2 will read it.  Many cheaper 3rd party tools won't.

Less likely to be the well known ECU fault, as that impacts the later Bosch units, fitted from 98 onwards.

Given the age and the climate you live in, check the reluctor rings for signs of corrosion, and the sensor brackets are sound and have the sensors at the right distance from the reluctor rings.  This can be done without diag tools.

Beyond that, I probably would try to acquire some diags tools that can read it, to understand what the ECU thinks is wrong.

Title: Re: ABS light on
Post by: dave the builder on 06 October 2020, 20:08:19

is the older ABS the bosch system previously fitted to senator/omega A /carlton with the ABS ECU under the seat  :-\ (not part of the pump manifold assembly)
in which case there is 2 replaceable relays under a cover on the ABS pump plus another surge arrest relay elsewhere

Title: Re: ABS light on
Post by: TheBoy on 06 October 2020, 21:39:25

Quote from: dave the builder on 06 October 2020, 20:08:19

is the older ABS the bosch system previously fitted to senator/omega A /carlton with the ABS ECU under the seat  :-\ (not part of the pump manifold assembly)
in which case there is 2 replaceable relays under a cover on the ABS pump plus another surge arrest relay elsewhere

No :)

Title: Re: ABS light on
Post by: MonzaGSE on 07 October 2020, 05:53:20

Thanks for all answers. Will check the sensors and rings this weekend. If nothing looks off i will take it to Opel next week.