'02 Impala - Cruise Control doesn't work

[Anaudiophile]

A buddy of mine has an '02 Impala - 3.8L - with the cruise control not working. Fuses ( 2 in left dash ) are good. The cruise control module connector looks good and there is power to the module over one of the white wires in the 10 pin connector. Cable is intact too. Anyone have a similar problem? The "cruise" light on the dash doesn't come on anymore either when trying to set the cruise.
Even a wiring diagram would help at this point!
thx

[stuzman]

Originally Posted by Anaudiophile

A buddy of mine has an '02 Impala - 3.8L - with the cruise control not working. Fuses ( 2 in left dash ) are good. The cruise control module connector looks good and there is power to the module over one of the white wires in the 10 pin connector. Cable is intact too. Anyone have a similar problem? The "cruise" light on the dash doesn't come on anymore either when trying to set the cruise.
Even a wiring diagram would help at this point!
thx

I have a 2004 Imala, so I'll assume the wiring diagrams are similar. On my diagrams, there are two white wires going to the module which is located at pins "G" and "J". There should be no voltage at pin "G" until the brake switch is applied. This switch is also used to operate the brake lights. The two wire colors on this switch are white and orange. At pin "J", this signal goes to the PCM to tell it that the cruise control module is engaged. The info on the cruise control connector is shown below:

Pin A: gray - cruise control on switch signal: 12VDC with cruise switch on
Pin B: dark blue - cruise control set/coast switch signal: 12VDC with switch pressed
Pin C: gray/black - cruise control resume/accel switch signal: 12VDC with switch pressed
Pin D: brown - cruise control release signal: 12VDC with brake pedal not pressed: 0V when pressed
Pin E: black/white - ground
Pin F: brown - ignition 3 voltage: 12VDC with ignition on
Pin G: white - stop lamp switch signal: 0V with brake pedal not pressed: 12VDC when pressed
Pin H: dark green - cruise control inhibit signal: 0V if PCM detects an inhibit condition
Pin J: white - cruise control engaged signal: voltage (unsure of value, either 12VDC or 5VDC) when signal engaged
Pin K: dark green - vehicle speed signal: 1 to 5 volts depending on speed


This view of connector is facing it after it is separated.

After posting the connector view, the lines don't quite line up, but at least it should show you the pin positions.
________________________
| | |
| F | G H J K |
| | |
| E | D C B A |
|__|___________________|

[Anaudiophile]

Awesome.........thanks for the info. It should be easy to see if the '04 wiring is the same. Now I have something to work with. Thanks again!

[crazy4nitro]

My Cruise Light comes on,then my A/C Fan stops working.

I found this Info about replacing the Ignition Switch which seemed to Fix most everybodys problem. I'm gonna give it a try.
On Page 2 a person stated that he made sure the wiring on the back of the Ignition Switch was secure and it solved his problem.

http://www.topix.com/forum/autos/che...RGSTUT9IFHS015

I will post my results when I get into the issue a little deeper.

'Nitro

[chevymandan]

i have an 04 impala and have troubleshot the problem with the above info. I know it's an old thread, but it is high on the search results list so hope it helps someone. Stuzman's info is good. The way I tested it might be different. Only thing that would be different is pin H.

Unplug cruise control module.
Using 2 pieces of thin wire (speaker wire or thermostat) put one end in Pin E which is the ground, and the other end wrapped around the negative lead of the meter. Take the other wire and put it in the Pin you want to test and the other end wrapped around the positive lead. Now you can test all the pins without using another person. Test on Volts DC

You can test all of them except for Pin K and Pin H at this point

To test Pin K, hook up the same way and I placed the wire on the rubber (between the hood and windshield wipers)and closed the hood. Rolled down the window and put the wires through the opening so the wires dont get pinched. Put the meter to Volts AC and have someone else in the car to drive or watch the meter.

To test Pin H, hook up the same way, but put the meter on Ohms. When you get to a certain speed, temp, and everything is good, the PCM will put the circuit to ground, which will show a closed circuit (close to 0.1 ohms) on your meter. You will notice when you hit the brakes you will get an open (OL) between the two.

[la1]

resist the temptation to force the meter probe into the connector socket or to back probe the connector....probably the BCM or the connectors. Might try some electrical contact cleaner on the removed connector , both halves.

[chevymandan]

my whole system checked out good so i replaced the cruise module with part ACDelco 12575408 which replaced the GM12575443 for my vehicle. I got it on Ebay new and shipped for $97. Easy to install if you have any sense. I finally got my Cruise light back on and it works like a champ.