G/box: 850 Auto: Auto Transmission warning light

[stevepcar]

Recently got 1996 850 20v T5 back on the road after a 7-year lay off. Got it through the MOT fairly easy, but shortly after on a short test run (upto 70 ) the Auto Transmission light came on (Flashing Arrow) Also the cruise control was not working. So after consulting the forum I was advised to do an oil flush (the oil was dark brown, so obviously needed changing ) I carried the flush out with all necessary topping up of the oil as I did it & used correct Dextron 111 oil. Took it for another test run, (the light had gone out) but after about 5-miles running up to 70, the light came on again, this was shortly after I had tried the cruise control. The gears were all changing smoothly. I limped home & just before I switched off I noticed that the green E light was flashing. I have the following questions:
1. I know that the cruise control is not working, therefore if I had not tried to turn it on, would the warning light come on anyway to register the faulty CC ?
2: Anybody have any idea why the cruise control is not working? I was hoping that changing the oil would have solved that problem.
3: Why was the E light flashing, even though I had not pressed it?
4: Can I get a code using my DIY flash code reader, that would tell me the problem?

I am a complete novice with Volvo Auto g boxes. My other car is a manual 850.
Any help/advice would be welcome.

[acshortt5]

You need to read the autobox fault codes and go from there. It could be a wide number of things from something internal, a solenoid, a speed sensor, the pnp switch or possibly the econ/sport/winter switch.

It is normal that the econ/sport/winter lights flash (along with the arrow on the dash) when there is a fault.

Your cruise control is powered by a vacuum pump located under the battery. An oil change on the autobox will not affect the operation of the cruise on it's own. Check the cruise control unit to see if a vac hose has come off.

I don't know 100% how you would read codes on yours, I think there is a section on this in the "articles" section or hopefully someone else who knows will be along soon or failing that you could get your local volvo dealer to read the codes.

[winsox]

Originally Posted by stevepcar

Recently got 1996 850 20v T5 back on the road after a 7-year lay off. Got it through the MOT fairly easy, but shortly after on a short test run (upto 70 ) the Auto Transmission light came on (Flashing Arrow) Also the cruise control was not working. So after consulting the forum I was advised to do an oil flush (the oil was dark brown, so obviously needed changing ) I carried the flush out with all necessary topping up of the oil as I did it & used correct Dextron 111 oil. Took it for another test run, (the light had gone out) but after about 5-miles running up to 70, the light came on again, this was shortly after I had tried the cruise control. The gears were all changing smoothly. I limped home & just before I switched off I noticed that the green E light was flashing. I have the following questions:
1. I know that the cruise control is not working, therefore if I had not tried to turn it on, would the warning light come on anyway to register the faulty CC ?
2: Anybody have any idea why the cruise control is not working? I was hoping that changing the oil would have solved that problem.
3: Why was the E light flashing, even though I had not pressed it?
4: Can I get a code using my DIY flash code reader, that would tell me the problem?

I am a complete novice with Volvo Auto g boxes. My other car is a manual 850.
Any help/advice would be welcome.

First of all before you get too involved with the gearbox the usual thing that fails on these is the PNP switch.

This sits on top of the gearbox which is used to tell the ECU what gear you have selected. overtime that get dirt in there and the ECU gets confused and throws an error code up and can sometimes put your gearbox into limp home mode.

the only way of telling for certain if to connect up and read the codes out of it. At the moment you're guessung what can be causing the fault.

if you decide to take the PNP switch off and give it a clean make sure you remember and mark it's position so you can put it on exactly where it came off otherwise the the switch won't be in the correct position one way of doing this is to align it in reverse and look at the tail lights put it in reverse as you would normally do this setting with the ignition on and the engine not started and move the the switch one way until the lights go out then move it the other way until they come on and then go out again and put it midway.

Also it will take a couple of drives for the light to extinguish itself after a self check you do really need the software to reset the gearbox tcu