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Contents Wiring diagrams Section: Cruise Control Systems All sections

Cruise Control System Chevrolet Corvette C6

Cruise Control Systems 1 illustration ~3854 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
DTC P0572 or P0573P0572: Brake Switch Circuit 1 Low Voltage P0573: Brake Switch Circuit 1 High Voltage
DTC P0575P0575: Cruise Control Switch Signal Circuit
DTC P0703P0703: Brake Switch Circuit 2

DIAGNOSTIC CODE INDEX

Diagnostic Starting Point - Cruise Control

Begin the system diagnosis with the Diagnostic System Check - Vehicle . The Diagnostic System Check will provide the following information

  1. The identification of the control modules which command the system
  2. The ability of the control modules to communicate through the serial data circuit
  3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Diagnostic Instructions

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
B+1B3794 08B3794 08
Cruise Control Switch Signal1B3794 081B3794 08
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 set/coast and resume/accelerate 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.

Conditions for Running the DTC

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

Conditions for Setting the DTC

  1. The BCM detects an invalid voltage signal on the cruise control switch signal circuit.
  2. The above condition is present for greater than 1 second.

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»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__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 and Set as the applicable switch is pressed.

Circuit/System Testing

  1. Ignition OFF, disconnect the X1 harness connector at the turn signal/multifunction switch.
  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. Test for B+ between the B+ circuit terminal 1 and the signal circuit terminal 5. 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 X2 harness connector at the BCM.
  5. Test for infinite resistance between the signal circuit terminal 61 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 turn signal/multifunction switch.

Component Testing

  1. Disconnect the X1 harness connector at the turn signal/multifunction switch.
  2. Cruise control switch ON, measure the resistance between terminal 1 and terminal 5 while individually activating 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 signal/multifunction switch.
Function SwitchMinimum Resistance ValueMaximum Resistance Value
OffO.L.O.L.
On7.1k Ohms8.6k Ohms
SET1.2k Ohms1.3k Ohms
+ RES2.8k Ohms3.0k Ohms

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Turn Signal Multifunction Switch Replacement»(/chevrolet/corvette/c6-2004-2014/remont/steering-column-switches/#steering-wheel-and-steering-column)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming
  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
Stop Lamp Switch SignalP0572P0572P0573

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

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

P0572

The ECM detects a low voltage signal on the stop lamp switch signal circuit when the serial data message from the BCM indicates the brakes are applied.

P0573

The ECM detects a high voltage signal on the stop lamp switch 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 becomes 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

  1. «Exterior Lights Schematics»(/chevrolet/corvette/c6-2004-2014/remont/exterior-lights/#lighting-systems)
  2. «Cruise Control Schematics»(/chevrolet/corvette/c6-2004-2014/remont/cruise-control-systems/#cruise-control-system)

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Ignition OFF, disconnect the harness connectors at the appropriate control modules listed below. ECM X1 TCM X400
  2. Connect a test lamp between the appropriate signal circuit terminal listed below and ground. ECM terminal 7 TCM terminal 6
  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 signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  4. Ignition OFF, connect the X400 harness connector at the TCM.
  5. Connect a test lamp between the ECM X1 harness connector signal circuit terminal 7 and ground.
  6. 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 signal circuit for a short to voltage. If the circuit tests normal, replace the TCM. If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the TCM.
  7. 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»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__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 malfunction indicator lamp (MIL) will not illuminate.
  2. The cruise control system is disabled.
  1. The DTC becomes history when the conditions for setting the DTC are no longer present.
  2. The history DTC clears after 40 consecutive warm-up cycles.

Schematic Reference

Connector End View Reference

Description and Operation

Electrical Information Reference

  1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Verify that DTC B3794 is not set. If the DTC is set, refer to «DTC B3794»(/chevrolet/corvette/c6-2004-2014/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 sets, replace the BCM. Clear the DTC, road test the vehicle and attempt to engage cruise. If DTC P0575 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

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The body control module (BCM) monitors the brake pedal position sensor. When the brake pedal is applied, the BCM detects a predetermined voltage signal. The BCM sends a serial data message to the engine control module (ECM) indicating the status of the stop lamps.

The engine is ON.

  1. The ECM receives an invalid brake pedal status serial data message from the BCM.
  2. This diagnostic runs continuously.
  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»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

  1. Verify that DTC P0572 or P0573 is not set. If either DTC is set, refer to «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) .
  2. Verify that DTC P0703 is not set. If DTC is set, replace the BCM. Clear the DTC and road test the vehicle. If DTC P0703 resets, replace the ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Brake Pedal Position Sensor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/exterior-lights/#lighting-systems__brake-pedal-position-sensor-replacement)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__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. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) , before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data link.
  2. Review the system operation in order to familiarize yourself with the system functions. Refer to «Cruise Control Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/cruise-control-systems/#cruise-control-system__cruise-control-description-and-operation) .

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the Cruise Control System. Refer to «Checking Aftermarket Accessories»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__checking-aftermarket-accessories) .
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could 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 system.

  1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
  2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
  3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal Performance
B+1B3794 08B3794 08
Cruise Control Switch Signal1B3794 081B3794 08
1. Cruise Control Malfunction

The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control set/coast and resume/accelerate 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»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
  2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
  3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
  4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__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 and Set as the applicable switch is pressed.

  1. Ignition OFF, disconnect the X1 harness connector at the turn signal/multifunction switch.
  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. Test for B+ between the B+ circuit terminal 1 and the signal circuit terminal 5. 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 X2 harness connector at the BCM.
  5. Test for infinite resistance between the signal circuit terminal 61 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 turn signal/multifunction switch.
  1. Disconnect the X1 harness connector at the turn signal/multifunction switch.
  2. Cruise control switch ON, measure the resistance between terminal 1 and terminal 5 while individually activating 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 signal/multifunction switch.
Function SwitchMinimum Resistance ValueMaximum Resistance Value
OffO.L.O.L.
On7.1k Ohms8.6k Ohms
SET1.2k Ohms1.3k Ohms
+ RES2.8k Ohms3.0k Ohms

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

  1. «Turn Signal Multifunction Switch Replacement»(/chevrolet/corvette/c6-2004-2014/remont/steering-column-switches/#steering-wheel-and-steering-column)
  2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM replacement, setup, and programming

Removal Procedure

  1. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection (LS7 or LS9)»(/chevrolet/corvette/c6-2004-2014/remont/charging-system/#battery-charging-system-starting-system) or «Battery Negative Cable Disconnection and Connection (LS3)»(/chevrolet/corvette/c6-2004-2014/remont/charging-system/#battery-charging-system-starting-system) .
  2. Remove the LH instrument panel (I/P) lower insulator panel. Refer to «Instrument Panel Insulator Panel Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
  3. Disconnect the clutch pedal cruise control release switch electrical connector (1).
  4. Remove the clutch pedal cruise control release switch (1) from the bracket.

Installation Procedure

  1. Install the clutch pedal cruise control release switch (1) to the bracket.
  2. Fully seat the switch in the bracket. Audible clicks will be heard while pushing the switch inward.
  3. Rotate the threaded switch to adjust it to the closed position when the clutch pedal is fully released.
  4. Connect the clutch pedal cruise control release switch electrical connector (1).
  5. Secure the clutch pedal cruise control release switch wiring harness to a surrounding wiring harness. Ensure that operation of the clutch pedal does not contact the clutch pedal cruise control release switch wiring harness or cause the switch to rotate.
  6. Install the LH I/P lower insulator panel. Refer to «Instrument Panel Insulator Panel Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
  7. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection (LS7 or LS9)»(/chevrolet/corvette/c6-2004-2014/remont/charging-system/#battery-charging-system-starting-system) or «Battery Negative Cable Disconnection and Connection (LS3)»(/chevrolet/corvette/c6-2004-2014/remont/charging-system/#battery-charging-system-starting-system) .

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 clutch pedal position (CPP) sensor, if equipped with a manual transmission
  5. The cruise control on/off switch
  6. The engine control module (ECM)
  7. The + RES switch
  8. The - SET switch
  9. The throttle actuator control (TAC) motor
  10. The vehicle speed sensor (VSS)

The BCM monitors the signal circuit of the cruise control switches. The BCM relays the cruise control switch status to the 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 throttle actuator control (TAC) motor in order to maintain the vehicle speed. For further review of the TAC System, refer to Throttle Actuator Control (TAC) System Description .

Ignition voltage is supplied to the cruise control switch from the 2-ampere CRUISE SW fuse located in the integrated BCM fuse block. 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 sends a 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

  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 engine control module (ECM) will engage the Cruise Control System and record the vehicle speed. The ECM sends a serial data message to the body control module (BCM). The BCM then sends a serial data message to the head-up display (HUD) in order to illuminate the Cruise Speed SET XXX message. 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.

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 cruise control On/Off 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 or to Brake Pedal Position Sensor Calibration . Pressing the clutch pedal while the cruise control is engaged will also disengage the cruise control system. The ECM monitors the CPP sensor via the CPP sensor signal circuit as the voltage signal decreases while the pedal reaches the fully applied position.

The cruise control system will also disengage when the cruise control on/off switch is switched OFF. The BCM sends a serial data message to the ECM in order to disengage the cruise control system. The BCM then sends a serial data message to the HUD in order to turn OFF the Cruise Speed SET XXX message. 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 cruise control system will also disengage when the ECM detects that a driver override function has been active for approximately 60 seconds.

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. A Cruise Control System DTC has been set.
  2. The vehicle speed is less than 40.2 km/h (25 mph).
  3. The vehicle speed is too high.
  4. The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear.
  5. The engine RPM is too low.
  6. The engine RPM is too high.
  7. The system voltage is not between 9-16 volts.
  8. The Antilock Brake System (ABS)/Traction Control System (TCS) is active for more than 2 seconds.