Hello all,

My cruise control has not worked since I bought this car last july(95 850 N/A wagon). I read the codes while in A7, the cruise control slot, and it flashed 1-2-2, which is a bad speed sensor. How do I go about replacing this? Is there anything else that would throw this code? And if the speed sensor is bad, would it cause the speedometer to act weird, which mine is not? I really want to try to get the cruise control system running since I'm going to be driving the car to school in the fall.

Thanks

 

The first thing you should know: Codes don't tell you what is wrong with the car. They tell you what part is sending a signal that the computer is not expecting, or something to that effect. A likely cause of this problem is an issue in the wiring between the speedometer and the cruise control module. Your best bet is to get hold of a wiring diagram and start tracing wires. If this doesn't help, post here again, and we'll see what we can do.

 

Hey thanks for the quick response. When I said "speed sensor" originally, I assumed, "speed sensor and all associated wiring". So I know that there could be a problem with wiring that is causing the code, and not the actual sensor itself. My bad, that was vague. But anyway, I'll definitely try to source a wiring diagram and see what I can do (Electronics are not my strong point haha). If there was a problem with this circuit at all, would it have an effect on my speedometer? Is that a different circuit or totally different sensor? Thanks for the help! I really appreciate any advice you guys can give me.

 

Cruise will ALLWAYS flash 1-2-2 when you read the codes, IF you did not testdrive the car prior to that. It tells you only that the car did not reach the 35 mph which enables the cruise function (safety issue).

In order to properly read the codes for Cruise you need to do as follows:
- Put the flylead into B2 not A7 (which is instument cluster btw).
- Drive the car with speeds above 35mph. Try all Cruise functions (+,-,resume etc)
- Stop somewhere "safe" and most important : DO NOT TURN OFF THE ENGINE!
- Read the codes.

If you turn off the engine, all errors are cleared, and the next time you try to read 1-2-2 greets you.

A very common cause for cruise to stop working are the switches at the brake and (if fitted) clutch pedal. They can be readjusted as follows:
Take the lid underneath the dashboard on the drivers side away (3x Torx 25).

For each pedal (brake and clutch ) do
{
Press the pedal with the hand down
Pull the "nose" of the black switch in which a small hose goes out.
Slowly let the pedal come back, the swich will self adjust now
}

Happy crafting
Cristian

 

Hey thanks for the tip. I did the test as you said, and wouldn't you know it, It flashed a 1-1-1 code. I took the panel off and tried to adjust the clutch and brake switch but I'm not sure if I did it properly. Is there anyway you could post a picture of the nose that you pull? Also, do you pull it out and hold it as you release the pedal?

 

I marked in the pic with red the part you have to pull out.
Press the pedal with the hand all the way down.
Then with the other hand pull the "nose" from the switch out of the switch. It will make some rattle noises.
When it's out let the pedal slowly come back. The same rattle noise will be "produced" as the pedal now pushes the nose back.

Also check that the 2 switches are firmly mounted, however be advised the 2 noses which hold them are prone to break if tampered with.

If this will not solve the problem I have a fault tracing PDF where you can check each function of the cruise system including the vacuum

Now I remember something else:
Check that the vacuum hose is mounted on the pump underneath the battery. Normally you should be able to see it without taking out the battery holder.

 

Thank you very much. I'll give that a try and see if it works out

 

When I got my first 850 the cruise did NOT work. I pulled the battery tray and found the vacuum tubes worn through. If you look in the DIY sticky, you'll see the cruise repair. If you don't have a error code, you likely have a vacuum or linkage problem.

I once had a loose linkage under the dash at the vacuum ball.

 

Yes... Vacuum problems are common. Volvo is kind of weird in that they use a vacuum pump for their cruise control units, instead of engine vacuum. So a vacuum leak in the cruise control isn't noticeable like it is on systems that use engine vacuum.