Thread: Multifunction switch cruise control

So, this question is likely for a seasoned tech or someone with access to the GM factory service manual ( I have some of both). A lifetime ago, I was an ASE certified tech (just not in diag).

Primary problem = No cruise control.
I do have a many of the pdf's from factorypdfservicemanuals.com I think it may be missing some pages but anyway...
I do have a DVOM and full diag scan tool that displays all the data stream.

So here is the deal, I think I may have a defective (and new) multifunction (turn/cruise) switch.
I just replaced this switch due to the bright lights coming on when not desired (turn cancel/or on etc.)
And now the cruise doesn't function, and the cruise did function prior to repair. (so likely a new bad switch).

Because this R&R of the switch is so intensive (Steering wheel/Air bag removal) - I would like a 2nd opinion.

Bright lights problem is solved. Turn signals, and all other light functions appear to be working correctly.

DTC's = No MIL light and no current codes but there is a history code = DTC P0564 Cruise Control MultiFunction Switch Circuit.
For this code GM repair guide gives ohm values to test for (on switch side) of the connector...To test between terminals 1 and 5.

This is the part I have having trouble verifying, as there are three male connectors (on switch) labeled alpha and then a 2-wire (female) coming out of the switch (no ID marks found on it).
So which are terminals 1 and 5?
There are other DVOM tests suggested, but until I can verify the terminal numbers or take everything back apart, this would be difficult if not impossible.

I did have trouble disconnecting this 2-wire during 1st repair and the wiring diagram says the cruise wires are PK (pink?) and GY (gray?) ....But the 2 wires on the switch are pink and black...
Did I damage the other side of connector during removal?

Is it just me or are these diagram colors sometimes wrong??? (seen it b4)

Testing and details so far....

The 2amp cruise switch (passenger dash side) is ok.

The brake lights work and the data stream shows TCC/Cruise Brake pedal released.

Datastream "Cruise" = disabled

Datastream "Cruise Inhibit Signal C" = On but next line = Fault (this sounds bad)

Cruise Set/Coast switch = always shows "off" No matter tap or long press.

Cruise Resume/Accel SW = always "off" No matter tap or long press.

My scan tool doesn't record (i think) but, do I have to be at the minimum 25 mph for this to show any of these coast/resume values to change?

The only value I have observed to change is the "Cruise On/Off switch" does seem to be operating correctly.
(switch on = value = on) (switch off = value = off)
If I hold the "S/C or R/A" switches the "Cruise On/Off switch value" = off and then back on when released ...this might be normal as well.

So we know it is getting power

Service manual says to observe the data stream when turning wheel lock to lock, if any changes, This will help eliminate the possibility of an internally shorted inflatable restraint steering wheel module coil. = No changes observed.
And no Air Bag light on.

I would attach pics of the datastream but I am limited to 142KB - is this, what pics today are that small?
If you want to see them PM me with your email and I can share them via Gmail.

Can you review and verify the wiring diagram questions?, so I can test the ohm values and verify before just putting in another switch? (and my bolded questions)?

Any other testing you can suggest? PLEASE HELP

people on tap talk cant see sig's. why its best to note year make model in the body of the post.

hes got a 2007 Pontiac Grand Prix (base) 3.8L N/A L26 as per his sig.

Originally Posted by KCprix

I find it sad.... I searched this forum throughly before making this post. Many said check the simple things like fuses and brake light switch.
I checked everything others suggested and when i put the detail in my post of others seasoned techs suggested... Not one of those people whom had the XP responded.

I find it sad that you found this sad.