'99 S70 Base, N/A, Auto -- Cruise control INOP troubleshooting

[E Showell]

So, the cruise control is officially dead, but the new ETM and battery reset appear to have extinguished the CEL. Any suggestions for cruise control diagnosis? I'll be headed for a junkyard next week.. any parts I should lay in for cruise control repair, or that should be picked up " just in case?"

[abscate]

What's the symptom? No cruise light turn on when you slide the switch?

[E Showell]

No light and when I slide the switch then use the rocker switch on the end of the stalk to increase speed, I get no increase and when I take my hand away, the speed starts declining.

[abscate]

First thing to check

Cruise bulb working? Car off, turn key to II , and see if cruise light comes on.

If it does, and won't turn on with the slider, it's probably the slider switch. When I get back from trip I will do some Pinout measurements. This maybe involve electrical work, fair warning

My - button my cruise stalk went INOP about a year or five ago, so now that we have more than one car to fix its time for me to deal with it.

[precopster]

Just so you know that a 98 stalk is the same part number as a 99 or 2000 model.

If you're looking in the junkyards this may help.

An 850 cruise stalk MAY work but is black in color.

On a 99 or 2000 the only parts are the stalk and software. Nothing else makes up the cruise circuit on these newer canbus cars.

If the ETM has a minor code such as BPPS (brake pedal position switch on the booster) the cruise stops working, however you would have a CEL if that were the case.

[E Showell]

So could be as simple as a bad stalk?

[abscate]

I would guess odds of bad stalk on a 99 at 93% if the cruise light doesn't come on.

When my ETS problem came on my 1999, the cruise light comes on but will not engage. By the way, the cruise won't work after a CEL reset for some period of 10s of minutes of driving on ME7 (1999) cars

Poster on crack,,,,the cruise light did NOT come on in this case...wrong car.

[precopster]

The cruise light only comes on at the commencement of plus (+) or minus (-) operation of the speed selection on 99 and 00 P80s which then indicates that cruise function has control of the vehicle.
As soon as you brake the cruise light turns off.

This is unlike P2s where the cruise light comes on when the cruise circuit is ready.

This then leaves the ON/OFF switch on the cruise stalk as the main suspect because it's unlikely that both plus and minus switches have failed at once.

BTW have you tried to activate cruise control with just the minus switch??

[E Showell]

Haven't tried just the "-". Will do and I'll report back, but probably not before the weekend.

[abscate]

Thanks Mike,,,sorry for the bad info. Too many cars confused me.

Cruise light comes on when engaged not energized.