Can't retrieve codes through dash an cruise control. Also cruise set resume switch does not seem to work.

step 1
Remove the left sound insulator
step 2
the stop switch is here, way way up top
use flash light to see it.
it is there.
top of pedal it is there. SM books step1.

buy the service manual.?
if the switch ever sticks on , cruise ENDS
it is a NO, switch normally open contarts
no calibration is stated so its PnP

Which engine ?
Cruise Control Description and Operation (3.6L)
Cruise Control Description and Operation (3.4L)

Do you know what all is involved in C.C. operation ?


Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions at speeds above 40km/h (25 mph). However, steep grades may cause variations in the selected speeds. The main components of the cruise control system are:
• The cruise control module assembly
• The cruise control switches
• The cruise control release switch
• The powertrain control module (PCM)
• The stoplamp switch assembly
• The vehicle speed sensor


The cruise control module controls the operation of the cruise control system. The cruise control module monitors the signal circuits of the cruise control switches. When the normally open cruise On/Off switch closes with a switch activation, the cruise control modules detects a high voltage on the signal circuit. The cruise control module activates the cruise control system.The set/coast switch and the resume/accel switch will not operate the system when the cruise control module has not activated the system based on the cruise control on/off switch signal circuit .
The cruise control module monitors the cruise control set/coast switch in order to determine when to capture and maintain the vehicle speed. The cruise control module monitors the vehicle speed signal circuit in order to determine the desired speed. The PCM pulses the vehicle speed signal circuit at 4000 pulses per minute. After an initial set speed has been established, the cruise control module also uses the cruise control set/coast switch signal circuit in order to tap down the set speed when the cruise control module detects a switch activation.
The cruise control module monitors the cruise control resume/accel switch signal circuit in order to determine when to resume the previous set speed. This feature only works within the same ignition cycle and as long as the cruise wasn't turned off using the cruise control On/Off switch since the last cruise engagement. After the set speed has been resumed, the cruise control module also uses the cruise control resume/accel switch signal circuit in order to tap up the set speed when the cruise control module detects a switch activation.
The cruise control module assembly has a controller and an electric stepper motor to vary the throttle in each different cruise control mode. Two components in the module assembly help to do this. The electronic controller and the electric stepper motor. The controller monitors vehicle speed and operates the stepper motor. The stepper motor operates in response to the controller, to maintain the desired cruise speed. The electric stepper motor moves a strap that is attached to the cruise control cable which moves the throttle

Any code's stored in the cruise control ?
DTC P0567 (4.8L, 5.3L, 6.0L, and 8.1L)
DTC P0567 (6.6L)
DTC P0568 (4.8L, 5.3L, 6.0L, and 8.1L)
DTC P0568 (6.6L)
DTC P0571 (4.8L, 5.3L, 6.0L, and 8.1L)
DTC P0571 (6.6L)
DTC P1574
The cruise control Resume/Accel switch is an input to the throttle actuator control (TAC) module. The TAC module uses the cruise control resume/accel switch signal circuit in order to detect when the driver has requested to accelerate the set vehicle speed or to resume the cruise control system. The TAC module detects a voltage signal on the cruise control resume/accel switch signal circuit when the switch is applied. The TAC module sends a serial data signal to the powertrain control module (PCM) via the UART serial data circuit. This DTC sets if the PCM receives a serial data signal from the TAC module indicating that voltage is present on the cruise control resume/accel switch signal circuit for longer than 90 seconds.

Does the vehicle have Throttle Actuator Control - electronic throttle control ?

Which engine does your trailblazer have 5.3 or 4.2 L
Cruise Control Description and Operation (5.3L)
Cruise Control Description and Operation (4.2L)
makes a difference ! The best way to start diagnostic's is with a scan tool . May have DTC'S diagnostic trouble codes .
DTC P1574 Stop Lamp Switch Circuit
DTC P0568 Cruise Control Set Switch Circuit
DTC P0567 Cruise Control Resume Switch Circuit
Plus with a scan tool you can see if the cruise control switch is inputing to PCM. Data list .
The cruise control resume/accel switch is an input to the powertrain control module (PCM). The PCM uses the cruise control resume/accel switch signal circuit in order to detect when the driver has requested to accelerate the set vehicle speed or to resume the cruise control system. The PCM detects a voltage signal on the cruise control resume/accel switch signal circuit when the switch is applied. This DTC sets if the PCM senses voltage on the cruise control resume/accel switch signal circuit for longer than 90 seconds.
Cruise Control Indicator Inoperative (4.2L)
Turn OFF the ignition.
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With the scan tool, Command the Cruise Control Lamp Test parameter ON, in the instrument panel cluster (IPC) Output Controls.
Does the Cruise indicator illuminate in the IPC?
YES - Go to Step 3
no - Go to Step 4
3
Inspect for poor connections at the harness connector of the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
YES - Go to Step 7
NO - Go to Step 6
4
Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?
YES - Go to Step 7
NO - Go to Step 5
5
Replace the IPC. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?
YES - Go to Step 7
--
6
Replace the PCM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?
Go to Step 7
--
7
Operate the system in order to verify the repair.
Does the system operate properly?
System OK
Go to Step 2

Cruise Control Inoperative/Malfunctioning (4.2L)

Install a scan tool.
Turn ON the ignition, with the engine OFF.
Press the cruise ON/OFF switch OFF.
With the scan tool, observe the Cruise ON/OFF switch parameter in the powertrain control module (PCM) Cruise Control Data list.
Does the Cruise ON/OFF switch parameter display OFF?

Your best bet mite be to take your vehicle to the dealer .

It is HVAC 1fuse #39 in the rear fuse block ,this powers the on/off switch for cruise control ! Fuse Block - Rear Beneath the left rear seat. What engine does it have ? 4.2 L or 5.3 l There is no vacuum involved in the operation of the cruise control ! Your vehicle has electronic throttle control .
Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions at vehicle speeds above 40 km/h (25 mph). Steep grades may cause variations in the selected vehicle speeds.
The following are the main components of the Cruise Control System:
?€¢
The powertrain control module (PCM)

?€¢
The On/Off switch

?€¢
The Resume/Accel switch

?€¢
The Set/Coast switch

?€¢
The TCC brake switch

?€¢
The stop lamp switch

?€¢
The throttle actuator control (TAC) motor

?€¢
The vehicle speed sensor

Cruise Control Engaged
The cruise control system will engage and adjust the vehicle speed based on the activation of the following cruise control switches:
?€¢
On/Off

?€¢
Resume/Accel.

?€¢
Set/Coast

The cruise control switches are located on the multifunction/turn signal lever.
The powertrain control module (PCM) monitors the signal circuits of the cruise control switches in order to determine when to capture and maintain the selected vehicle speed. The PCM uses the throttle actuator control (TAC) module motor in order to control the vehicle speed. For further information on the TAC System, refer to Throttle Actuator Control (TAC) System Description in Engine Controls - 4.2 L.
Ignition positive voltage is supplied from the 10 ampere HVAC 1 fuse to the cruise control switch via the ignition 3 voltage circuit. When the normally open cruise control On/Off switch is turned On, the switch closes and the PCM detects a high signal voltage on the cruise control on switch signal circuit. When the normally open Set/Coast switch is pressed, the switch closes and the PCM detects a high signal voltage on the cruise control set/coast switch signal circuit. To engage the cruise control system, turn the On/Off switch On and momentarily press the Set/Coast switch. The PCM will confirm that the cruise control enable criteria has been achieved. The PCM will engage the cruise control system and record the selected vehicle speed. The PCM sends a class 2 message to the instrument panel cluster in order to illuminate the cruise control indicator. Pressing the accelerator pedal, while the cruise control system is engaged, will allow the driver to override the cruise control system in order to accelerate the vehicle beyond the current set vehicle speed. When the accelerator pedal is released, the vehicle will decelerate and resume the current set vehicle speed. The driver can also override the current set vehicle speed via the Set/Coast switch and the Resume/Accel switch. When the cruise control system is engaged, pressing and holding the Set/Coast switch will allow the vehicle to decelerate from the current set vehicle speed without deactivating the cruise control system. When the Set/Coast switch is released, the PCM will record the vehicle speed and maintain the vehicle speed as the new set vehicle speed. When the cruise control system is engaged, momentarily pressing the Set/Coast switch will allow the vehicle to decelerate at 1.6 km/h (1 mph) increments for each time that the Set/Coast is momentarily pressed, with a minimum vehicle speed of 37 km/h (23 mph). When the normally open Resume/Accel switch is activated, the switch closes and the PCM detects a high signal voltage on the cruise control resume/accel switch signal circuit. Activating and holding the Resume/Accel switch, when the cruise control system is engaged, will allow the vehicle to accelerate to a greater vehicle speed than the current set vehicle speed. When the Resume/Accel switch is released, the PCM will record the vehicle speed and maintain the vehicle speed as the new set vehicle speed. When the cruise control system is engaged, momentarily activating the Resume/Accel switch will allow the vehicle to accelerate at 1.6 km/h (1 mph) increments for each time that the Resume/Accel switch is momentarily activated, with the maximum acceleration total of 16 km/h (10 mph) over the current set vehicle speed . Momentarily activating the Resume/Accel switch, after the cruise control system has been disengaged by pressing the brake pedal, will recall the previous set vehicle speed that is recorded in the PCM.

Bummer deal! This may be a way to tell you some tail lights are burnt out. Some cruise controls have a fuse in a second location.
The fuse is not in right or is blown. Check with a new fuse. Hope this helps. ...gc http://www.auto-tune-up-and-repair-options.com/

you need to turn on the key switch (do not 
start truck) Set parking brake (light on, on dash) then depress the cruise on and resume switches 
at the same time. this will bring the code up on the 
odometer display. then turn on the left turn signal and 
press the cruise on and the cruise set switches at the same time once or twice and the code should clear out.

Once you have turned your cruise control on accelerate to desired speed press SET button on right hand side of steering wheel before lifting foot from accelerator, then remove foot from accelerator. pushing RESUME button will deactivate cruise control without turning it off. Then when clear of traffic push resume again to activate cruise control. It will automatically resume to previous set speed.

There are a few things you can try. First, check your
brake lights, if they do not work the problem may be
in the stoplight sw circuit. Also there are 3 fuses you
can check, 1 is a 25amp in the fuse block under the
hood the next 2 are in the fuse block under the dash.
One is the 15amp stoplight fuse and the other is a
10amp turn sig fuse. These fuses are either directly
or indirectly related to the cruise ctrl. Next check the
cruise switchs accel/coast set/resume if either sw.
was sticking in any posistion for 90 seconds or more,
the cruise ctrl. will shut down. There are trouble codes that will set but they won't trip the check engine light. You'll need an obdII scanner to recover
them from the memory. If you don't have one, go to
autozone/napa or advance auto parts they will scan it
free. The codes of interest are po571 stoplight switch
po567 and po568 the cruise ctrl switch's. And any
other codes related to the torque converter clutch -
the speed sensor - throttle actuator control.
Hope this helps. Good luck.

The cruise-controls have 2-buttons that must be activated before it gets the car going when you remove your foot off the gas-pedal.
The cruise button is essentailly a switch that turns 'on' the cruise servo-motor that tells the sytems that you wants to use it, so it gets ready.
There are other three switches on the right-side of the steering wheel namely: resume accel; cancel; set decel.
To get your car to cruise: you must steady your speed and foot on the gas-pedal. You cannot just press the switches and expect the car to cruise. It takes about two-to-three seconds for the system to respond to a set cruising speed.
How to do it: accelerate to a speed of about 30-mph. Press the 'cruise' button on the dash first. Next you press 'set decel' button. This will turn 'on' the cruise control light on the instrument panel. Then wait a second or three and you would feel the cruise engagement. Any touch on the brake pedal will slow down the car and turns the cruise off. The 'cancel' button turns off the cruise light on the instrument panel.
If you hit the brake-pedal at any time for any reason, and you would like to continue cruising again, simply press the 'resume accel' button.
The cruise system works in conjunction with the braking system of the car. So all major parts of the braking system must be in good condition, otherwise the cruise system could shut off itself.