Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[jtypecav]

Can someone modify my first post to say that it goes away when designated an auto.

Many thanks!

[TheBoy]

(The master tech tried FULL conversion and partial designation - not sure what this meant, but only full designation back to auto got rid of the gremlins again..)

Sounds like a bit of Billy Bull. Certainly not the terminology used on Tech2 or TIS.

[jtypecav]

Think he used the term designation - Something to do with just the engine vs. the whole system.

But agree, was hoping for more of an idea...

[AndyStobbs]

Think if this was my car and I was keen to try and sort it on my own, given what you've already replaced I would get a known good manual ECU and go through the coding. Expensive for you as you've got to pay someone for the coding, or replace the thing as an ecu kit.

The car should not be killing off random cylinders with any coding. Can get you some wiring diagrams for auto vs. manual if you need them.

[jtypecav]

The I see where you are coming from. I had thought the same too. The thing is..

The auto ECU was a known good one. It seems crazy to think that when reprogrammed as a manual that it replicates an ecu I binned over a year ago and the fault still be with this separate ECU. It's got to be something else.

If it helps, the calculated engine load on live data is all over the place. But when tested individually the thottle pedal / butterflies are accurate.

[TheBoy]

If it helps, the calculated engine load on live data is all over the place. But when tested individually the thottle pedal / butterflies are accurate.

Can you get live data readings on the MAF?

[jtypecav]

I will certainly have a go. But I've been thinking.. ( )

If the difference is between auto and manual. Physically, what connections / sensors do each of them have. Because in both cases the main car ECU *would* be expecting data. So auto ecu expecting a gearbox ecu the throws up spanner coz all data from there is missing... but... what if the manual gearbox has something like a sensor that's true faulty state is being hidden behind the autobox ECU so:

a) with manual ecu faulty signal is sent from something on the gearbox (speed?) and received badly
b) With auto ecu the mig just shrugs saying I've not received anything from the gearbox and carries on!

Thinking logically, that's the only direction the fault can lie in. So what data comes from gearbox on both transmissions? Anything that a missing GB ECU would inhibit that a manual GB receives must be the issue.

Tell me there's a speed (or other) sensor on the gb the ecu gives a damm about??! That when removed from equation the car ignores and continues to function?>!!

[Entwood]

Thinking about your last post .. and a previous one ... you said that when you go AUTO the car "works" fine but the EML light is on ... what code is the EML giving ?? because that "might" be the signal that is missing/faulty ??  EML code only appears when a fault is detected ....

"The problem goes away when erroneously told it's an auto - the spanner comes on, and it drives beautifully."

[jtypecav]

It would be helpful if it did, but it just registers a generic misfire, occasionally also detailing cyls 3 and 6. (from memory)

It also doesn't store any code once ign is off and on again.

Just thinking what could mess the load values up... had assumed the speed was from abs... but.. gearboxes "do" motion.. but it could be something else.. whatever it is.. the missing auto ecu could be shielding this from getting through to the main car ecu - whatever it is, that's the reason it runs sweet!

[jtypecav]

I've noticed on the how-to section, and on this box here that "5) Remove the electrical connector at the back of the gearbox."

Anyone know what that's for? Was assuming that reverse switch would be in linkage / or gaiter area. If not, apologies for my lack of savvy here.

[AndyStobbs]

Thinking about your last post .. and a previous one ... you said that when you go AUTO the car "works" fine but the EML light is on ... what code is the EML giving ?? because that "might" be the signal that is missing/faulty ??  EML code only appears when a fault is detected ....

"The problem goes away when erroneously told it's an auto - the spanner comes on, and it drives beautifully."

It will be something along the lines of lost communication with gearbox module, or service light on at the request of gearbox module, or control module not coded etc.

I had a look on the wiring diagrams before and the abs and auto box and steering angle sensor all share the same pins on the engine ecu. Speed signal on a manual will come from abs, speed signal on an auto could come from the prop shaft or the abs.
Would be interesting to pull abs fuse and see if the speed signal still arrived on the auto.
All this is speculative though as first and foremost is establishing WHY the cylinders drop out and how, is it actually the ignition timing, ignition itself or injector?

My plan of attack would be to find that first. If cylinders are losing fuel or spark that's a massive fault and completely undesirable state of affairs. NOTHING should do that, only on the over-run should the injectors drop out. Sparks should never drop out if the rest of the system is healthy.

[AndyStobbs]

I've noticed on the how-to section, and on this box here that "5) Remove the electrical connector at the back of the gearbox."

Anyone know what that's for? Was assuming that reverse switch would be in linkage / or gaiter area. If not, apologies for my lack of savvy here.

Rear most sensor is output speed. Gearbox needs that to know when to change gear.

[jtypecav]

Does a manual ECU still hear "gearbox speed" signial..

because.. if it does... I've listed all the things GM TCU's "typically" take in:

Input parameters[edit]

The typical modern TCU uses signals from engine sensors, automatic transmission sensors and from other electronic controllers to determine when and how to shift. More modern designs share inputs or obtain information from an input to the ECU, whereas older designs often have their own dedicated inputs and sensors on the engine components. Modern TCUs are so complex in their design and make calculations based on so many parameters that there are an indefinite amount of possible shift behaviours.

Vehicle speed sensor (VSS)
Wheel speed sensor (WSS)
Throttle position sensor (TPS)
Turbine speed sensor (TSS)
Transmission fluid Temperature sensor (TFT)
Kick down switch
Brake light switch
Traction Control System (TCS)
Cruise control module

And from that VSS and WSS seem most likely problem. Car sees WOT and no speed... goes into limp?

The spanner is only on due to missing autobox TCU correct!

[Kevin Wood]

Engine, Gearbox ECU and ABS system are connected by a CAN link (steering angle and yaw sensor are sometimes shown, but they are only present on Omegas with ESP, and I've never seen that on a UK car).

If the devices detected on the CAN link are not consistent with the ECU config then errors will be raised.

ABS system measures vehicle speed and this is routed to other systems as a separate square wave signal. IIRC, it doesn't go to the autobox. This has its' own output shaft signal, as said, and gets input speed from engine RPM via CAN. It may also get vehicle speed via CAN, of course.

The fault really sounds like the engine ECU going into limp home for some reason, as it's odd to get a misfire starting at 4k RPM.

Can't think what it might be, though. ABS system not happy, perhaps? I could see it going into such a state if ABS and TC are known not to be functional due to a misconfigured CAN bus, for example, but you'd get the ABS and TC lights on then, surely?

It really needs a few hours with a Tech2, as has been said. Happy to oblige if you ever pass Hampshire...

[jtypecav]

ABS and TCS working fine (with latter switch-able!). But vehicle load... How is this calculated? On auto ECU it's correct, on manual ECU it's wrong. With auto designation there is never, ever, ever, limp or performance loss? I don't think it's 4k per se. More a perceived load / speed conflict.

THIS: Is 1st / 2nd gear map from last year. (look at EML blinking and right before for any clues?)
http://img440.imageshack.us/img440/506/1stgeargood2ndgearbadsp.png

Here's the rather redundant original thread: (yes I've driven it for a year+ with the wrong ecu till now!)
http://www.omegaowners.com/forum/index.php?topic=104473.0