Scan Tool Data Definitions Disengage History
The Cruise Control Scan Tool Definitions - Disengage History is a common
list for all of the available cruise control disengagement definitions available
on the scan tool. The cruise control system equipped on the vehicle determines which
cruise control disengagement parameters are available on the scan tool.
One of the following conditions must be present in order for a disengagement
parameter to appear:
• | The cruise control system is active and disengagement is requested. |
• | The engagement of the cruise control system is requested while a fault
is present. |
Accel Rate: The powertrain control module (PCM)/engine control
module (ECM) detects that the vehicle acceleration is greater than the calibrated
cruise control threshold.
Bad Sequence: The PCM/ECM detects that a cruise control software
execution error is present.
Brake: The PCM/ECM detects that the stop lamps have been activated
or the PCM/ECM detects that a stop lamp pedal activation had not occurred before the
cruise control system was requested.
Cancel: The PCM/ECM detects that the cruise control cancel switch
has been activated.
CC Sw. Position: The PCM/ECM detects that the acceleration mode
is active without the activation of the Accel. switch.
Clutch: The PCM/ECM detects that the clutch pedal switch has
been activated.
Clutch Switch: The PCM/ECM detects that the clutch pedal switch
has been activated.
Cruise Off: The PCM/ECM detects that the cruise On/Off switch
was turned to OFF when the cruise control system was enabled.
Coast Low Speed: The PCM/ECM detects that the Set/Coast switch
is activated until the vehicle speed is below 37 km/h (23 mph).
Coast Disengage: When the PCM/ECM detects that the cruise set/coast
signal is active and the throttle blade fully closes the cruise control system will
disengage until the PCM/ECM detects that the set/coast signal is inactive. The cruise
control system will then engage and set with the new vehicle speed.
Decel Rate: The PCM/ECM detects that the vehicle deceleration
is greater than the calibrated cruise control threshold.
DTC Set: The PCM/ECM detects that a DTC has been set which affects
the cruise control operation.
Engine Run Time: The PCM/ECM detects that the cruise control
system has been requested and the engine run time counter is not active.
Engine Speed: The PCM/ECM detects that the engine speed is less
than or greater than a calibrated RPM.
ETC: The PCM/ECM detects a fault within the throttle actuator
control (TAC) system.
First Gear: While the cruise control system is active, the PCM/ECM
detects that the transmission is in Drive 1.
High Accel.: The PCM/ECM detects that the vehicle acceleration
is greater than the calibrated cruise control threshold.
High Decel.: The PCM/ECM detects that the vehicle deceleration
is greater than the calibrated cruise control threshold.
High Speed: The PCM/ECM detects that the vehicle speed is greater
than the calibrated amount.
Illegal Mode: The PCM/ECM detects that the acceleration mode
is active without the activation of the Accel. switch.
Injector Disable: The PCM/ECM detects that the engine is overspeed
and that the fuel shutoff has been activated.
Low Speed: The PCM/ECM detects that the vehicle speed is less
than 37 km/h (23 mph) while the cruise control system was enabled.
Low Voltage: The PCM/ECM detects that the ignition voltage is
below 9 volts.
Manual/Neutral: The PCM/ECM detects that transmission is in
Neutral, Reverse or Park.
Memory Corrupt: An internal PCM/ECM memory fault is detected.
MPH Limit: The PCM/ECM detects a that the vehicle is overspeed
and that the fuel shutoff has been activated.
No History: This parameter is displayed when a new PCM/ECM has
been installed.
None: This parameter is displayed when a new PCM/ECM has been
installed.
Off: The PCM/ECM detects that the cruise On/Off switch was turned
to OFF when the cruise control system was enabled.
Over Set Speed: This parameter is displayed when the current
vehicle speed is greater than the set vehicle speed by more than a calibrated amount.
Over Speed: This parameter is displayed when the current vehicle
speed is greater than the set vehicle speed by more than a calibrated amount.
Over Speed Tap: This parameter is displayed when the Set/Coast
switch is briefly applied while the current vehicle speed is greater than the set
vehicle speed by more than a calibrated amount.
Pedal Initialize: The PCM/ECM detects that a stop lamp pedal
activation had not occurred before the cruise control system was requested.
PCM Error: The PCM/ECM detects that a cruise control software
execution error is present.
PCM Inhibit: The PCM/ECM detects a RAM corruption associated
to the cruise control system.
Pedal > Cruise: The PCM/ECM detects that the accelerator pedal
overrides the set vehicle speed for approximately 60 seconds.
Serial Data: A fault in the serial data circuit from the cruise
control switch to the platform module is detected.
S/C On, CC Off: When the PCM/ECM detects that the cruise set/coast
signal is active and the throttle blade fully closes the cruise control system will
disengage until the PCM/ECM detects that the set/coast signal is inactive. The cruise
control system will then engage and set with the new vehicle speed.
S/C On - Speed High: This parameter is displayed when
the Set/Coast switch is briefly applied while the current vehicle speed is greater
than the set vehicle speed by more than a calibrated amount.
Stop Lamp Switch: The PCM/ECM detects that the stop lamps have
been activated.
TAC Inhibit: The PCM/ECM detects a fault within the TAC system.
Traction: The PCM/ECM detects that the traction control system
had been activated. It is also possible that a tire with low air pressure can also
set this disengagement reason.
Traction Loss: The PCM/ECM detects that the traction control
system had been activated. It is also possible that a tire with low air pressure can
also set this disengagement reason.
Two Commands: The PCM/ECM detects that the Set/Coast switch
and the Resume/Accel switch are active at the same time.
Two CC Commands: The PCM/ECM detects that the Set/Coast switch
and the Resume/Accel switch are active at the same time.
Under Speed: The PCM/ECM detects that the vehicle speed is less
than the cruise memory speed by more than a calibrated amount.
Under Set Speed: The PCM/ECM detects that the vehicle speed
is less than the cruise memory speed by more than a calibrated amount.
Scan Tool Data Definitions Cruise Control
The Scan Tool Data Definitions list contains a brief description of all of the
cruise control related parameters that are available on the scan tool. On vehicles
equipped with a 3.6L (LY7), an engine control module (ECM) is used. On vehicles equipped
with a 3.8L (L26), a powertrain control module (PCM) is used.
Cruise Control Active: The scan tool displays Yes or No. The
ECM/PCM determines the current status of the cruise control operation. An operating
cruise control system is displayed as Yes.
Cruise Disengage (1-8) History: The scan tool displays
the last 8 reasons why the cruise control system was disengaged. Refer to the Scan
Tool Data Definitions (Disengage History) for descriptions.
Cruise Inhibit Reason: The scan tool displays the reason why
the cruise control system is Inhibited. Refer to the Scan Tool Data Definitions (Disengage
History) for descriptions.
Cruise On/Off Switch: The scan tool displays On/Off. This is
the state of the cruise control On/Off switch as detected by the ECM/PCM. An active
switch is displayed as On.
Cruise Resume/Accel Switch: The scan tool displays On or Off.
This is the state of the resume/accel switch as detected by the ECM/PCM. An active
cruise resume and accel switch is displayed as On.
Cruise Set/Coast Switch: The scan tool displays On or Off. This
is the state of the cruise set switch as detected by the ECM/PCM. An active cruise
set switch is displayed as On. The cruise control On/Off switch must be On to view
the parameter correctly.
Engine Speed: The scan tool displays 0 to 9,999 RPM.
This is the engine RPM as monitored by the ECM/PCM. The ECM/PCM monitors the crankshaft
position (CKP) signal circuit in order to determine the engine RPM.
Ignition 1 Signal: The scan tool displays 0 to 25.5 volts.
The PCM monitors the voltage of the ignition 1 voltage circuit.
Initial Brake Apply Signal: The scan tool displays Applied/Released.
The body control module (BCM) monitors the signal circuit of the brake pedal position
sensor. When the PCM receives a serial data message from the BCM indicating that the
brake pedal has been applied, the scan tool displays Applied.
Reduced Engine Power: The scan tool displays Active or Inactive.
When the ECM/PCM detects that a malfunction in the throttle actuator control (TAC)
System exists, the scan tool displays Active.
Stop Lamp Pedal Switch: The scan tool displays Applied or Released.
The ECM/PCM monitors the stop lamp pedal switch signal circuit. An activated brake
pedal is displayed as Applied.
Stop Lamp Pedal Switch Signal: The scan tool displays Volts.
The PCM monitors the voltage of the stop lamp pedal switch signal circuit.
TAC/PCM Communication Signal: The scan tool displays OK or Fault.
The PCM uses the universal asynchronous receiver transmitter (UART) serial data circuit
in order to communicate with the throttle actuator control (TAC) module. A malfunction
in the UART serial data circuit is displayed as Fault.
TAC Stop Lamp Pedal Switch: The scan tool displays Applied or
Released. The TAC module monitors the stop lamp pedal switch signal circuit. An activated
brake pedal is displayed as Applied.
TAC Vehicle Speed Signal: The scan tool displays Ok or Fault.
The PCM determines the status of the vehicle speed signal circuit to the TAC module.
A malfunction in the vehicle speed signal circuit is displayed as Fault.
TCC Brake Pedal Switch: The scan tool displays Applied or Released.
The ECM monitors the status of the brake pedal. An activated brake pedal is displayed
as Applied.
Traction Control Status: The scan tool displays Active or Inactive.
When the ECM/PCM detects that a traction control condition exists, the scan tool displays
Active.
Vehicle Speed Circuit History: The scan tool displays OK/Open/Short/Invalid
State. The PCM detects and determines the history of the vehicle speed circuit.
Vehicle Speed Circuit Status: The scan tool displays OK/Fault/Invalid
State. When the PCM detects that a malfunction in the vehicle speed signal circuit
exists, the scan tool will display Open or Short.
Vehicle Speed Sensor: The scan tool displays 0-255 km/h
(0-155 mph). The ECM/PCM monitors the vehicle speed sensor signal in
order to calculate the vehicle speed for display.