I have a '94 cavalier 2.0 16V ecotec. The engine light keeps coming on and it's hesitant a lower revs. The fault codes displayed are 75 'torque control - low (transmission switch)' & 76 'torque control - continuous (transmission switch)'.
Can anyone explain the fault and where is that 'transmission switch'?
Many thanks
howy686
Edited by Pugugly {P} on 12/01/2008 at 21:05
|
Is your car automatic?
Number_Cruncher
|
That's odd, because torque control is a fault code that only makes sense for an automatic.
On an automatic cavalier, at the point where the automatic gearbox is about to change up, the gearbox sends a torque control signal to the engine management unit. The engine management unit, in response retards the ignition timing, smoothing the change. After the gearbox has changed gear, the torque control signal is switched off.
This code is set if the torque control signal persists for longer than normal.
However, it is very odd that your car is giving this code. I would check to make sure that your car's ecu is in manual mode - the mode can be read off the F0 data list in Tech1, I don't know if there is another way to get at this data. The ECU is coded, manual, or automatic by earthing a wire - sorry, I don't know which one!
It is also possible that the wiring for the torque control signal is present in your car, and is shorting to earth, thus presenting a torque control signal where one isn't expeected. If the ecu is retarding the ignition, I would expect the car to respond very sluggishly to accelerator input; but, once the trouble code is set, it is also possible that the ecu simply ignores this signal.
You need to check the wiring diagram for both manual and automatic versions of this engine. Find the differences between the two diagrams, and then check to make that everything is right on your car.
Sorry about the essay!
Number_Crncher
|
No problem - I'm grateful for the detailed reply. Seems that my ECU is totaly confused. Looks like I'll have to find a specialist to sort this out.
Many thanks.
|
I've had a bit of a dig about.
Terminal 42 of the ECU multiplug is the coding wire;
For manual transmission it should be earthed
For automatic transmission it should be connected to the park/neutral switch.
Terminal 51 of the engine ECU multiplug is the wire from the automatic gearbox ecu (terminal 13) - This wire shouldn't even be present on your car, but if it is, make sure that it floats, i.e., make sure it isn't connected to earth - or anything for that matter!
Also check that you have a good earth to pin 19, the elctronics earth.
If all of this checks out correctly, I would suggest having the ECU checked out off the car before going further (unless you can get hold of a spare ECU to check with very cheaply!)
Number_Cruncher
|
Thank-you,
that saves me going into the loft.
Kevin...
|
|
|
(unless you can get hold of a spare ECU to check with very cheaply!)
As it's a 94 Cavalier, won't he also need the pick up that goes around the steering column and key with the chip in that are both married up to the spare ECU so that the immobiliser can be overridden?
|
The OP *may* be lucky, and not have this system but he should check anyway - good point DD.
Number_Cruncher
|
|
|
|
|
