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[P6UL K]

Afternoon one and all,

Can anyone explain in detail how the traction control works on the Omega?  Mine is playing up and sometimes turns itself on or off at will and on occasions when i try to turn it off it won't turn off or if i do mangae to turn it off, it stays off for a bit and then turns itself back on again!  Very frustrating!

Does it run thru the ecu off of the rear ABS sensors or is it much more complicated than that?

Ta 

[Kevin Wood]

The speed of the driven wheels are monitored through the ABS system and, if a wheel is slipping, the brakes on that side are applied to transfer the torque to the other back wheel. If that doesn't work the system talks to the engine ECU which responds by dropping cylinders and/ or retarding the ignition to reduce power on the non-dbw cars. DBW cars appear to lose power by reducing throttle, as it's smoother.

If the TC light is ON the system has been disabled by pressing the button OR there's a fault with it. If the light's off the system is enabled (this is the default after starting the car).

It sounds to me like there's a fault which is causing it to light the TC light, to be honest.

[2woody]

cars up to about 1998.....

no brake intervention.
ECU drops cylinders

cars from 1998 up to DBW.....

brake intervention and ignition retard

DBW cars.....

throttle opening reduction

[P6UL K]

Sounds well complicated!

So if i turn it off from the switch its 100% disabled?  Might change the switch first then incase that is faulty....

[Kevin Wood]

Sounds well complicated!

So if i turn it off from the switch its 100% disabled?  Might change the switch first then incase that is faulty....

If you press the switch so the light is on, TC is disabled. If the light is off, it's enabled.

I've never known a switch to fail. What are the symptoms? If you start up and drive off the light is off, yes? If it comes on of its' own accord I'd say you have a fault and it's indicating a stored fault code.

I would get the ABS codes read before doing much else, TBH.

[TheBoy]

To clarify what Kevin Wood and 2woody have said:

The system is enabled if the light on the dash is OFF, and disabled if the light is ON

Pre 1998 cars, TC cuts cylinders

Post 1998 cars, TC applies brake to rear wheel that is losing traction, if that does not resolve the situation, will start to cut cylinders (2.5/3.0) or reduce throttle (2.6/3.2)

[albitz]

Sounds well complicated!

So if i turn it off from the switch its 100% disabled?  Might change the switch first then incase that is faulty....

I might have a switch here you can have just to eliminate it Paul.If you want to nip up and see me when Im at work,I should be able to read the codes for you too.

[albitz]

Should say - switch is FOC to Paul as I owe him a favour.Not trying to sell anything in this area.

[TheBoy]

Sounds well complicated!

So if i turn it off from the switch its 100% disabled?  Might change the switch first then incase that is faulty....

I might have a switch here you can have just to eliminate it Paul.If you want to nip up and see me when Im at work,I should be able to read the codes for you too.

Its a simple Push To Make switch, thus if you just remove the switch, the system should remain enabled (dash light OFF) inless there is a fault.

[P6UL K]

Thanks for all your detailed answers fellas, much appreciated!

I get how its meant to work, my issue is that on occasions when i do decide to turn it off it just won't - no matter how hard or repeated press the button    It just won't turn off, then sometimes it will turn on and off like it should which makes me think its the switch or the wiring behind as the switch wasn't there when i got the car, the police used the +feed for some of the equipment.

[P6UL K]

Sounds well complicated!

So if i turn it off from the switch its 100% disabled?  Might change the switch first then incase that is faulty....

I might have a switch here you can have just to eliminate it Paul.If you want to nip up and see me when Im at work,I should be able to read the codes for you too.

Car is OTR at the moment mate as the drivers door lock mechanism needed sorting (cheers Twiggy ) and i'm trying to sort the battery drain that is causing the NEW battery to go flat in 2-3 days as well as the T/C issues, just want to sort a few niggles.

Any chance of popping that switch in the post 

[albitz]

Assuming I can find it yep.Will have a look in the morning and let you know.As said,it may well not be that,but at least you can eliminate it from your enquiries.

[Kevin Wood]

Thanks for all your detailed answers fellas, much appreciated!

I get how its meant to work, my issue is that on occasions when i do decide to turn it off it just won't - no matter how hard or repeated press the button    It just won't turn off, then sometimes it will turn on and off like it should which makes me think its the switch or the wiring behind as the switch wasn't there when i got the car, the police used the +feed for some of the equipment.

Sounds like the switch has been wired to something that's not always active, IMHO. If the plod have messed about with the wiring anything's possible.

I'll have a look at the wiring diags when I get a chance and see how it's supposed to be wired.

[2woody]

the police used the +feed for some of the equipment.

would have saved time if you'd said that first. The shoddy nature of the Police wiring will undoubtedly be the cause.

I'm on my fourth Police car now - every single modification to all of them by Police has been done in a less than competent fashion - some of them downright dangerous.

[P6UL K]

Thanks for all your detailed answers fellas, much appreciated!

I get how its meant to work, my issue is that on occasions when i do decide to turn it off it just won't - no matter how hard or repeated press the button    It just won't turn off, then sometimes it will turn on and off like it should which makes me think its the switch or the wiring behind as the switch wasn't there when i got the car, the police used the +feed for some of the equipment.

Sounds like the switch has been wired to something that's not always active, IMHO. If the plod have messed about with the wiring anything's possible.

I'll have a look at the wiring diags when I get a chance and see how it's supposed to be wired.

Ah that would be smashing, thanks Kevin