Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Tolak on 30 July 2008, 22:31:33

Title: Automatic Gearbox Fault on 2.5 Diesel
Post by: Tolak on 30 July 2008, 22:31:33
Car drives only on get-you-home throttle (1k rpm) but seems to have no problem with gearbox (gears select, no noise from 'box)
Display a fault on the display "Automatic Gearbox".
Check the codes from the ECU, and I get 21 and 92.
21 = Accelerator Position Sensor Signal Voltage High
92 = Cruise Control Device Circuit Open or Voltage High

Codes from ECU seem to relate to lack of throttle.
But what is causing the "Automatic Gearbox" message?
And so how do I move on to fixing it?
Thanks,
Tom

EDIT: When I said "No problem from the box" I meant that there were no undue noises, etc. I think that the box was not auto-changing, and was only running under manual control from the lever.  This apparently means that the controler was not active; whether by its own actions or by "force majeur", I don't know.
Title: Re: Automatic Gearbox Fault on 2.5 Diesel
Post by: Tolak on 31 July 2008, 13:13:05
Quote
Car seems to have no problem with gearbox (gears select, no noise from 'box)
Display a fault on the display "Automatic Gearbox".

But what is causing the "Automatic Gearbox" message?
And so how do I move on to fixing it?
Thanks,
Tom
I've stripped out the lack of throttle, on the assumption that the gearbox is the primary failure, and the ECU is protecting against that.

So how is the failure being detected? Oil pressure switch in the box?  Do these sensors (and wiring) fail? Since there is no noise from the box, and it seems to be operating OK (albeit only at low revs; I've not got throttle authority to say otherwise) I wonder if it is a sensor problem rather than an actual box problem.
But if it is actual failure, would failure of the gearbox pump cause a message like this, but still allow operation of the box?  Could it "just" be oil level, or is this likely to be terminal?
Title: Re: Automatic Gearbox Fault on 2.5 Diesel
Post by: HolyCount on 31 July 2008, 13:28:07
I am afraid I have no idea -- but I am sure someone who does will be along ...... however, from wandering throught the forum for a while it appears that 9 times out of 10 it's a sensor glitch ---- very few problems that turn out to be terminal !

Best of luck --- if anybody can suss it out this lot can  :y
Title: Re: Automatic Gearbox Fault on 2.5 Diesel
Post by: Tolak on 31 July 2008, 13:35:38
Quote
I am afraid I have no idea -- but I am sure someone who does will be along ...... however, from wandering throught the forum for a while it appears that 9 times out of 10 it's a sensor glitch ---- very few problems that turn out to be terminal !

Best of luck --- if anybody can suss it out this lot can  :y
I'm hoping that the intricasies of the interlocking controllers will be unravelled by the specialists on this site; I think this evening I'm going for a crawl around under the car to check the wiring and that all the gearbox sensors are fully in place.
But the lack of noise, reasonable operation of the gearbox, and safety override all point to a controller intervention, perhaps based on bad information, so I can live in hope...

PS Good luck with your bumper!
Title: Re: Automatic Gearbox Fault on 2.5 Diesel
Post by: tunnie on 31 July 2008, 15:03:49
how many miles on the TD?
Title: Re: Automatic Gearbox Fault on 2.5 Diesel
Post by: Tolak on 31 July 2008, 15:18:43
Quote
how many miles on the TD?
180k; unknown about details of other use, etc, but really tidy inside (esp in back), so probably not used as taxi, no tow hitch, etc. Previous owner only had it for about 3k miles, and had ECU trouble that has eroded his tolerance.
Title: Re: Automatic Gearbox Fault on 2.5 Diesel
Post by: Marks DTM Calib on 31 July 2008, 16:07:05
Well, I am not surprised, given that thier appears to be an issue with possibly the throttle pedal position , then this may affect the autobox as might not be able to detect kickdown etc
Title: Re: Automatic Gearbox Fault on 2.5 Diesel
Post by: Tolak on 31 July 2008, 16:42:20
Quote
Well, I am not surprised, given that thier appears to be an issue with possibly the throttle pedal position , then this may affect the autobox as might not be able to detect kickdown etc

So, from your experience, is the throttle affecting the gearbox, or the gearbox affecting the throttle?
Or are there two independant problems?
Can I unplug one controller from the other, so the problems can be show to be independant?  See similar questions in the electrical forum.  Central Display: Source of Information (http://www.omegaowners.com/forum/YaBB.pl?num=1217516069) and Inter-ECU communication (http://www.omegaowners.com/forum/YaBB.pl?num=1217516221)

As you say from the other thread, a Tech2 will tell us the controller's perception, and that's the useful start of the repair. But since the car's not usefully mobile, I'd like to try alternative methods (like unplugging) to isolate the faults if possible.
Title: Re: Automatic Gearbox Fault on 2.5 Diesel
Post by: TheBoy on 31 July 2008, 19:33:42
i would try to fix the 21 first. ignore the cruise one - just means no cruise stalk present.
Title: Re: Automatic Gearbox Fault on 2.5 Diesel
Post by: Marie on 31 July 2008, 19:44:37
have you checked the gearbox level? and has it had any oil change recently? look at the cheep options first.

i do know that TD's gearboxes are not built to last, and given its milage it might have given up the ghost ......but lets hope not hey. have a look at your oil sometimes something so simple can solve it!

good luck
Title: Re: Automatic Gearbox Fault on 2.5 Diesel
Post by: Tolak on 01 August 2008, 00:22:18
Quote
have you checked the gearbox level? and has it had any oil change recently? look at the cheep options first.

i do know that TD's gearboxes are not built to last, and given its milage it might have given up the ghost ......but lets hope not hey. have a look at your oil sometimes something so simple can solve it!

good luck

Would low oil level cause the "Automatic Gearbox" message on the display?
I shall be looking to check that the oil levels are correct; but don't believe any recent servicing was carried out shortly before the "failure".
Since I have no throttle, I cannot detect if I have clutch/band slip. Still trying to work out if the gearbox problem is disabling the throttle, which might seem appropriate. Back to the logic behind the "Automatic Gearbox" message, I think.

Reading the article (second link) on the Omega Auto Box Information (http://www.omegaowners.com/forum/YaBB.pl?num=1183545930) page makes me think the box is in manual mode, and only changes in response to the lever.
I've added this comment to the initial statement of problem:
Quote
When I said "No problem from the box" I meant that there were no undue noises, etc. I think that the box was not auto-changing, and was only running under manual control from the lever.  This apparently means that the controler was not active; whether by its own actions or by "force majeur", I don't know.
So the question is, has the box controller failed, and so left the box in manual mode, or has the box controller detected a failure, and so only allows the box to run in manual mode.

Will the Tech2 allow the box controller info be extracted? And who is there near here who can help with a Tech2?