Home ReviewsRefund
Home/Cadillac/CTS/Cadillac CTS II (2007-2014)/Repair manual/Cruise Control Systems/Cruise Control System
Contents Wiring diagrams Section: Cruise Control Systems All sections

Cruise Control System Cadillac CTS II

Cruise Control Systems 1 illustration ~3613 words

Scheme 1

Scheme 1: Cruise Control Schematics
Scheme 1: Cruise Control Schematics

DIAGNOSTIC CODE INDEX

DTCDescription
DTC B3794B3794 08: Cruise Control Function Request Circuit Signal Invalid B3794 61: Cruise Control Function Request Circuit Actuator Stuck
DTC P0571P0571: Cruise Control Brake Switch Circuit
DTC P0575P0575: Cruise Control Switch Signal Circuit

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
B+1B3794 081B3794 08, B3794 61
Cruise Control Switch Signal1B3794 08B3794 08B3794 08, B3794 61
1. Cruise Control Malfunction

Circuit/System Description

The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control on/off, set/coast, resume/accelerate and cancel switches via the cruise control switch signal circuit in order to detect when the driver has requested to perform a cruise control function. The BCM detects a specific voltage signal on the cruise control switch signal circuit when a switch is applied. The BCM sends a serial data message to the ECM indicating the status of the cruise control switches.

Conditions for Running the DTC

  1. The cruise switch is ON.
  2. The ignition is ON.

B3794 08

The BCM detects an invalid voltage signal on the cruise control switch signal circuit for 0.5 second.

B3794 61

Stuck switch for either Resume/Accel or Set/Coast button for 60 seconds.

Actions Taken When the DTC Sets

  1. The malfunction indicator lamp (MIL) will not illuminate.
  2. The cruise control system is disabled.

Conditions for Clearing the DTC

  1. The condition responsible for setting the DTC no longer exists.
  2. A history DTC will clear after 40 malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Engine ON, while rotating the steering wheel to both steering stops, observe the scan tool Cruise Control Switch parameter while pressing each of the cruise control switches. The parameter should toggle between On, Off, Resume, Set, and Cancel as the applicable switch is pressed.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the steering wheel controls switch - left.
  2. Ignition ON, test for B+ between the B+ circuit terminal 1 and ground. If less than the specified value, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  3. Ignition ON, test for B+ between the B+ circuit terminal 1 and the signal circuit terminal 2. If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  4. Ignition OFF, disconnect the X1 harness connector at the BCM.
  5. Test for infinite resistance between the signal circuit terminal 3 and ground. If less than the specified value, test the signal circuit for a short to ground.
  6. If all circuits test normal, test or replace the steering wheel control switch-left.

Component Testing

  1. Disconnect the harness connector at the steering wheel controls switch - left.
  2. Cruise control switch ON, measure the resistance between terminal 1 and terminal 2 while individually activation and holding each cruise control function switch and compare the resistance reading to the values in the table below. If not within the specified resistance range, replace the turn steering wheel controls switch - left.
Function SwitchMinimum Resistance ValueMaximum Resistance Value
OffO.L.O.L.
On6.5k Ohms7.1k Ohms
SET2.2k Ohms2.4k Ohms
+ RES3.7k Ohms3.9k Ohms
Cancel1.4k Ohms1.6k Ohms

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Steering Wheel Control Switch Assembly Replacement»(/cadillac/cts/ii-2007-2014/remont/memory-modules/#secondary-and-configurable-customer-control-system)
  2. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Stop Lamp Switch SignalP0571P0571P0571

The brake applied signal circuit is a high voltage input from the body control module (BCM) to the engine control module (ECM) and transmission control module (TCM). The ECM monitors the stop lamp switch circuit to detect when the brake pedal has been applied. The BCM monitors the brake pedal position sensor to determine when the brake pedal is applied. When the brake pedal is applied, the BCM supplies a high voltage signal on the brake applied signal circuit and also sends a serial data message to the ECM indicating that the brake pedal has been applied. The ECM senses a high voltage signal on the brake applied signal circuit when the brake pedal has been applied.

  1. The engine is running.
  2. Battery voltage is greater than 11.5 V.

Conditions for Setting the DTC

The ECM detects either a low voltage signal on the brake applied signal circuit when the serial data message from the BCM indicates the brakes are applied, or a high voltage signal on the brake applied signal circuit when the serial data message from the BCM indicates the brakes are not applied.

  1. The malfunction indicator lamp (MIL) will not illuminate.
  2. The cruise control system is disabled.
  1. The condition responsible for setting the DTC no longer exists.
  2. A history DTC will clear after 40 malfunction-free ignition cycles have occurred.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition OFF, disconnect the X2 harness connector at the ECM.
  2. Connect a test lamp between the control circuit terminal 52 X2 and ground.
  3. Ignition ON, verify the test lamp turns ON and OFF when pressing and releasing the brake pedal. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  4. If all circuits test normal, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM, ECM, or TCM replacement, setup, and programming

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When a cruise control function switch is activated, the body control module (BCM) detects a predetermined voltage signal. The BCM sends a serial data message to the engine control module (ECM) indicating the function that has been requested.

The ignition is ON.

  1. The ECM receives an invalid cruise control switch status serial data message from the BCM.
  2. This diagnostic runs continuously.
  1. The cruise control system is disabled.
  2. The malfunction indicator lamp (MIL) will not illuminate.
  1. The condition responsible for setting the DTC no longer exists.
  2. A history DTC will clear after 40 malfunction-free ignition cycles have occurred.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Verify that DTC B3794 is not set. If DTC is set, refer to «DTC B3794»(/cadillac/cts/ii-2007-2014/remont/cruise-control-systems/#cruise-control-system)
  2. Road test the vehicle and attempt to engage cruise. Verify that cruise control engages properly and the DTC P0575 is not set. If DTC resets, replace the BCM. Clear the DTC, road test the vehicle and attempt to engage cruise. If the DTC resets, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM or ECM replacement, setup, and programming

Symptoms - Cruise Control

IMPORTANTThe following steps must be completed before using the symptom tables.
  1. Before using the symptom diagnostic table, perform the «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-trouble-code-dtc-list) in order to verify the following conditions: There are no DTCs set. The module can communicate via the GM LAN.
  2. Review the system operation in order to understand the system functions. Refer to «Cruise Control Description and Operation»(/cadillac/cts/ii-2007-2014/remont/cruise-control-systems/#cruise-control-system__cruise-control-description-and-operation) .

Visual/Physical Inspection

  1. Inspect for aftermarket devices which can affect the operation of the Cruise Control System. Refer to «Checking Aftermarket Accessories»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .
  2. Inspect the accessible system components or the visible system components for obvious damage or for obvious conditions which can cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to Cruise Control Malfunction in order to diagnose the symptom.

  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
B+11
Cruise Control Indicator Control222
1. Cruise Control Malfunction 2. Indicator Lamp Malfunction

The cruise control switch contains a LED that illuminates to indicate the cruise control system has been switched ON. Voltage is applied through the ON/OFF switch to the LED when the switch is pressed. The BCM provides the ground path for the LED through a dedicated control circuit. Pressing the switch again opens the switch and the lamp turns OFF.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool Cruise Control Switch parameter. Verify the parameter changes each time the switch is pressed.

  1. If the parameter does not change, refer to «Cruise Control Malfunction»(/cadillac/cts/ii-2007-2014/remont/cruise-control-systems/#cruise-control-system) .
IMPORTANTRefer to DTC B3794 before performing this diagnostic, if this code is set as current or history.
  1. Ignition OFF, disconnect the harness connector at the steering wheel control switch-left.
  2. Ignition ON, verify that a test lamp illuminates between the low reference circuit terminal 7 and B+. If the test lamp does not illuminate, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  3. If all circuits test normal, test or replace the steering wheel controls switch-left.
  1. Disconnect the harness connector at the steering wheel controls switch - left.
  2. Cruise control switch ON, measure the resistance between terminal 1 and terminal 2 while individually activation and holding each cruise control function switch and compare the resistance reading to the values in the table below. If not within the specified resistance range, replace the turn steering wheel controls switch - left.
Function SwitchMinimum Resistance ValueMaximum Resistance Value
OffO.L.O.L.
On6.5k Ohms7.1k Ohms
SET2.2k Ohms2.4k Ohms
+ RES3.7k Ohms3.9k Ohms
Cancel1.4k Ohms1.6k Ohms

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Steering Wheel Control Switch Assembly Replacement»(/cadillac/cts/ii-2007-2014/remont/memory-modules/#secondary-and-configurable-customer-control-system)
  2. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
B+1B3794 081B3794 08, B3794 61
Cruise Control Switch Signal1B3794 08B3794 08B3794 08, B3794 61
1. Cruise Control Malfunction

The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control on/off, set/coast, resume/accelerate and cancel switches via the cruise control switch signal circuit in order to detect when the driver has requested to perform a cruise control function. The BCM detects a specific voltage signal on the cruise control switch signal circuit when a switch is applied. The BCM sends a serial data message to the engine control module (ECM) indicating the status of the cruise control switches.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
  2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
  4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Engine ON, while rotating the steering wheel to both steering stops, observe the scan tool Cruise Control Switch parameter while pressing each of the cruise control switches. The parameter should toggle between On, Off, Resume, Set, and Cancel as the applicable switch is pressed.

  1. Ignition OFF, disconnect the harness connector at the steering wheel controls switch - left.
  2. Ignition ON, test for B+ between the B+ circuit terminal 1 and ground. If less than the specified value, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  3. Ignition ON, test for B+ between the B+ circuit terminal 1 and the signal circuit terminal 2. If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  4. Ignition OFF, disconnect the X1 harness connector at the BCM.
  5. Test for infinite resistance between the signal circuit terminal 3 and ground. If less than the specified value, test the signal circuit for a short to ground.
  6. If all circuits test normal, test or replace the steering wheel control switch - left.
  1. Disconnect the harness connector at the steering wheel controls switch - left.
  2. Cruise control switch ON, measure the resistance between terminal 1 and terminal 2 while individually activation and holding each cruise control function switch and compare the resistance reading to the values in the table below. If not within the specified resistance range, replace the turn steering wheel controls switch - left.
Function SwitchMinimum Resistance ValueMaximum Resistance Value
OffO.L.O.L.
On6.5k Ohms7.1k Ohms
SET2.2k Ohms2.4k Ohms
+ RES3.7k Ohms3.9k Ohms
Cancel1.4k Ohms1.6k Ohms

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Steering Wheel Control Switch Assembly Replacement»(/cadillac/cts/ii-2007-2014/remont/memory-modules/#secondary-and-configurable-customer-control-system)
  2. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM or ECM replacement, setup, and programming

Cruise Control Description and Operation

Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions at 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

  1. The accelerator pedal
  2. The brake pedal position (BPP) sensor
  3. The body control module (BCM)
  4. The cruise on/off switch
  5. The cruise control cancel switch
  6. The + RES switch (equivalent to resume/accel switch)
  7. The - SET switch (equivalent to set/coast switch)
  8. The engine control module (ECM)
  9. The throttle actuator control (TAC) motor
  10. The vehicle speed sensor

The body control module (BCM) monitors the signal circuit of the cruise control switches, which are located on the steering wheel. The BCM relays the cruise control switch status to the engine control module (ECM) via a serial data message. The ECM uses the status of the cruise control switch to determine when to capture and maintain the vehicle speed. The ECM monitors the vehicle speed signal circuit in order to determine the desired vehicle speed. The ECM uses the TAC motor in order to maintain the vehicle speed. For further information on the TAC system, refer to Throttle Actuator Control (TAC) System Description .

Voltage is supplied to the cruise control switch via the steering wheel control switch reference voltage circuit supplied by the BCM. The cruise control function switches are arranged in a resistive ladder design, with each cruise control function switch having a different resistance value. The BCM detects a specific voltage value that is associated with the cruise control function switch being activated. When the normally open cruise control on/off switch is turned ON, the switch closes and the BCM supplies a ground to the cruise control switch ON indicator circuit as it becomes illuminated. The BCM sends a GMLAN serial data message to the ECM indicating that the on/off switch is active. Similarly, when the normally open + RES switch or the normally open - SET switch are pressed, the switch closes and the BCM detects the predetermined voltage signal on the cruise control resume/accel and set/coast switch signal circuit. The BCM sends a serial data message to the ECM indicating that the + RES switch or the - SET switch is active. The + RES switch or the - SET switch will remain inactive when the BCM has not received the predetermined voltage signal from the on/off switch.

Cruise Control Engaged

The cruise control system will engage and adjust vehicle speeds, based on the activation of the following cruise control switches, which are located on the steering wheel

  1. On/Off
  2. + RES
  3. SET

To engage the cruise control system, ensure that the vehicle speed is above 40.2 km/h (25 mph), turn the cruise On/Off switch ON and momentarily press the - SET switch. The ECM will engage the cruise control system and record the vehicle speed. The ECM sends a serial data message to the instrument panel cluster (IPC) in order to illuminate the Cruise Engaged indicator in the IPC.

Pressing the accelerator pedal while the cruise control system is engaged, allows 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 switch and the + RES switch. When the cruise control system is engaged, pressing and holding the - SET switch will allow the vehicle to decelerate from the current set vehicle speed without deactivating the cruise control system. When the - SET switch is released, the ECM 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 switch will allow the vehicle to decelerate at 1.6 km/h (1 mph) increments for each time that the - SET is momentarily pressed, with a minimum vehicle speed of 37 km/h (23 mph).

Pressing and holding the + RES 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 + RES switch is released, the ECM 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 + RES switch will allow the vehicle to accelerate at 1.6 km/h (1 mph) increments for each time that the + RES switch is momentarily pressed, with the maximum acceleration total of 16 km/h (10 mph) over the current set vehicle speed. Momentarily activating the + RES switch will recall the previous vehicle speed, after the cruise control system is disengaged by pressing the brake pedal, or CANCEL switch.

Cruise Control Disengaged

The engine control module (ECM) disengages the cruise control operation based on the signals from the following switches

  1. The brake pedal position (BPP) sensor
  2. The clutch pedal position (CPP) sensor, if equipped with a manual transmission
  3. The On/Off switch
  4. The cruise control cancel switch

The cruise control system will disengage when the brake pedal is applied. The body control module (BCM) monitors the BPP sensor via the BPP sensor signal circuit as the voltage signal increases while the pedal reaches the fully applied position. The ECM monitors the BPP signal through a discrete input and a serial data message signal from the BCM indicating the brake status. When both signals indicate the brake pedal is applied, the ECM will disengage the cruise control system. For further information on the BPP sensor, refer to Exterior Lighting Systems Description and Operation and to Brake Pedal Position Sensor Calibration .

The cruise control system will also disengage when the cruise control on/off switch is switched OFF, or the cruise control cancel switch is activated. The body control module (BCM) determines when the cruise control cancel switch is activated. When the normally open cancel switch is closed, the BCM detects the predetermined voltage signal on the cruise control function switch circuit. The vehicle speed stored in the memory of the engine control module will be erased when the cruise control On/Off switch is turned OFF, or the ignition switch is turned OFF. The BCM sends a serial data message to the ECM in order to disengage the cruise control system. The cruise control system will disengage when the ECM detects that a driver override function has been active for approximately 60 seconds. When the cruise control system has been disengaged, the ECM sends a serial message to the instrument panel cluster (IPC) in order to turn OFF the Cruise Engaged indicator.

Every time the cruise control system is disengaged, the ECM will keep track of the reason for system disengagement. The last 8 disengagement reasons will be recorded within the ECM memory. The scan tool will display the last 8 Cruise Disengage History parameters, in which one out of approximately 50 possible reasons will be displayed in each of these 8 parameters. For the disengagement reason to be displayed within the scan tool parameter either the cruise control system is active and disengagement is requested, or engagement of the system is requested but a fault is present. For a list of each disengagement reason along with each definition, refer to Control Module References in the ECM Scan Tool Information.

Cruise Control Inhibited

The engine control module (ECM) inhibits the cruise control operation when any of the following conditions exist

  1. The ECM has not detected a brake pedal activation from the body control module (BCM).
  2. A cruise control system DTC has been set.
  3. The vehicle speed is less than 40.2 km/h (25 mph).
  4. The vehicle speed is too high.
  5. The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear.
  6. The engine RPM is low.
  7. The engine RPM is high.
  8. The system voltage is not between 9 volts and 16 volts.
  9. The antilock brake system (ABS)/traction control system (TCS) is active for more than 2 seconds.