Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Cruise Control Indicator Always On (Without Throttle Actuator Control)
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Cruise Control Schematics Connector End View Reference: Cruise Control Connector End Views | ||||
| 1 | Did you perform the Cruise Control Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Cruise Control | |
| 2 | Turn the ignition ON, with the engine OFF. Does the Cruise indicator illuminate after the instrument panel cluster (IPC) displays test? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | |
| 3 | Turn the ignition OFF. Install a scan tool. Turn the ignition ON, with the engine OFF. With the scan tool, observe the Cruise Control parameter in the IPC data list. Does the Cruise Lamp parameter display On? | Go to Step 4 | Go to Step 9 | |
| 4 | Turn the ignition OFF. Disconnect the cruise control module. Turn the ignition ON, with the engine OFF. With a DMM, measure the voltage of the cruise control engaged signal circuit. Does the voltage measure at approximately the specified voltage? | B+ | Go to Step 7 | Go to Step 5 |
| 5 | Test the Cruise control engaged signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 6 | |
| 6 | Inspect for a poor connection at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 8 | |
| 7 | Replace the cruise control module. Refer to Cruise Control Module Replacement (4.3L Engine) . Did you complete the replacement? | Go to Step 10 | ||
| 8 | IMPORTANT: Program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls-4.3LDid you complete the replacement? | Go to Step 10 | ||
| 9 | Replace the Instrument Panel Cluster (IPC). Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 10 | ||
| 10 | Operate the system in order to verify the repair. Does the system operate properly? | System OK | Go to Step 2 | |
| IMPORTANT |
|---|
| Program the replacement PCM. |
Cruise Control Indicator Always On (Without Throttle Actuator Control)
Cruise Control Indicator Always On (With Throttle Actuator Control)
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Cruise Control Schematics Connector End View Reference: Cruise Control Connector End Views | |||
| 1 | Did you perform the Cruise Control Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Cruise Control |
| 2 | Turn the ignition ON, with the engine OFF. Does the Cruise indicator illuminate after the instrument panel cluster (IPC) displays test? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems |
| 3 | Turn the ignition OFF. Install a scan tool. Turn the ignition ON, with the engine OFF. With the scan tool, observe the Cruise Control parameter in the IPC data list. Does the Cruise Lamp parameter display On? | Go to Step 4 | Go to Step 5 |
| 4 | IMPORTANT: Program the replacement PCM. Replace the PCM. Refer to the appropriate procedure: Powertrain Control Module (PCM) Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L Engine Control Module (ECM) Replacement in Engine Controls - 6.6L (LLY) Engine Control Module (ECM) Replacement in Engine Controls - 6.6L (LB7) Powertrain Control Module (PCM) Replacement in Engine Controls - 8.1L Did you complete the replacement? | Go to Step 6 | |
| 5 | Replace the IPC. Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 6 | |
| 6 | Operate the system in order to verify the repair. Does the system operate properly? | System OK | Go to Step 2 |
| IMPORTANT |
|---|
| Program the replacement PCM. |
Cruise Control Indicator Always On (With Throttle Actuator Control)
Cruise Control Indicator Inoperative (Without Throttle Actuator Control)
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Cruise Control Schematics Connector End View Reference: Cruise Control Connector End Views | ||||
| 1 | Did you perform the Cruise Control Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Cruise Control | |
| 2 | Turn the ignition OFF. Install a scan tool. Turn the ignition ON, with the engine OFF. With the scan tool, Command the Cruise Control Lamp Test parameter ON, in the instrument panel cluster (IPC) Special Functions. Does the Cruise indicator illuminate in the IPC? | Go to Step 3 | Go to Step 8 | |
| 3 | Turn the ignition OFF. Disconnect the cruise control module. Turn the ignition ON, with the engine OFF. With a DMM, measure the voltage of the cruise control engaged signal circuit. Does the voltage measure at approximately the specified voltage? | B+ | Go to Step 4 | Go to Step 5 |
| 4 | Test the cruise control engaged signal circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 7 | |
| 5 | Test the cruise control engaged signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 6 | |
| 6 | Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 9 | |
| 7 | Replace the cruise control module. Refer to Cruise Control Module Replacement (4.3L Engine) . Did you complete the replacement? | Go to Step 10 | ||
| 8 | Replace the instrument panel cluster (IPC). Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 10 | ||
| 9 | IMPORTANT: Program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls-4.3L.Did you complete the replacement? | Go to Step 10 | ||
| 10 | Operate the system in order to verify the repair. Does the system operate properly? | System OK | Go to Step 2 | |
| IMPORTANT |
|---|
| Program the replacement PCM. |
Cruise Control Indicator Inoperative (Without Throttle Actuator Control)
Cruise Control Indicator Inoperative (With Throttle Actuator Control)
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Cruise Control Schematics Connector End View Reference: Cruise Control Connector End Views | |||
| 1 | Did you perform the Cruise Control Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Cruise Control |
| 2 | Turn the ignition OFF. Install a scan tool. Turn the ignition ON, with the engine OFF. With the scan tool, command the Cruise Control Lamp Test parameter On, in the instrument panel cluster (IPC) Special Functions. Does the Cruise indicator illuminate in the IPC? | Go to Step 4 | Go to Step 3 |
| 3 | Replace the IPC. Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 5 | |
| 4 | IMPORTANT: Program the replacement PCM. Replace the PCM. Refer to the appropriate procedure: Powertrain Control Module (PCM) Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L Engine Control Module (ECM) Replacement in Engine Controls - 6.6L (LLY) Engine Control Module (ECM) Replacement in Engine Controls - 6.6L (LB7) Powertrain Control Module (PCM) Replacement in Engine Controls - 8.1L Did you complete the replacement? | Go to Step 5 | |
| 5 | Operate the system in order to verify the repair. Does the system operate properly? | System OK | Go to Step 2 |
| IMPORTANT |
|---|
| Program the replacement PCM. |
Cruise Control Indicator Inoperative (With Throttle Actuator Control)
Conditions for Enabling Cruise Control
- The vehicle speed is greater than 40 km/h (25 mph).
- The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear.
- The system voltage is between 12 volts and 16 volts.
| Step | Action | Value | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Cruise Control Schematics Connector End View Reference: Cruise Control Connector End Views or Powertrain Control Module (PCM) Connector End Views in Engine Controls - 4.3L | ||||
| 1 | Did you perform the Cruise Control Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Cruise Control | |
| 2 | Turn the ignition OFF. Disconnect the cruise control module. Turn the ignition ON, with the engine OFF. Connect a test lamp between the ignition 3 voltage circuit and a good ground. Does the test lamp illuminate? | Go to Step 3 | Go to Step 5 | |
| 3 | Connect a test lamp between the ignition 3 voltage circuit and the ground circuit of the cruise control module. Does the test lamp illuminate? | Go to Step 4 | Go to Step 22 | |
| 4 | Turn the cruise control On/Off switch OFF. Connect a test lamp between a good ground and each of the following circuits: The cruise control on switch signal circuit The cruise control set/coast switch signal circuit The cruise control resume/accel switch signal circuit Does the test lamp illuminate for any of the signal circuits listed above? | Go to Step 12 | Go to Step 6 | |
| 5 | Turn the cruise control On/Off switch OFF. Connect a test lamp between battery voltage and each of the following circuits: The cruise control on switch signal circuit The cruise control set/coast switch signal circuit The cruise control resume/accel switch signal circuit Does the test lamp illuminate for any of the signal circuits listed above? | Go to Step 13 | Go to Step 21 | |
| 6 | Turn the cruise control On/Off switch ON. Connect a test lamp between the cruise control on switch signal circuit and a good ground. Does the test lamp illuminate? | Go to Step 7 | Go to Step 14 | |
| 7 | Connect a test lamp between the cruise control set/coast switch signal circuit and a good ground. With the cruise control On/Off switch ON, press and hold the Set/Coast switch. Does the test lamp illuminate? | Go to Step 8 | Go to Step 16 | |
| 8 | Connect a test lamp between the cruise control resume/accelerate switch signal circuit and a good ground. With the cruise control On/Off switch ON, press and hold the Resume/Accel switch. Does the test lamp illuminate? | Go to Step 9 | Go to Step 17 | |
| 9 | Connect a test lamp between the stop lamp supply voltage circuit and a good ground. Refer to Circuit Testing in Wiring Systems. Does the test lamp illuminate? | Go to Step 10 | Go to Step 19 | |
| 10 | With a DMM, measure the voltage from the vehicle speed signal circuit to a good ground. Refer to Circuit Testing in Wiring Systems. Does the voltage measure at the specified value? | B+ | Go to Step 11 | Go to Step 20 |
| 11 | With a DMM, measure the voltage from the cruise control engaged signal to a good ground. Refer to Circuit Testing in Wiring Systems. Does the voltage measure at the specified value? | B+ | Go to Step 25 | Go to Step 18 |
| 12 | Test the signal circuit that illuminated the test lamp for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 24 | |
| 13 | Test the signal circuit that illuminated the test lamp for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 24 | |
| 14 | Test the cruise control on/off switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 15 | |
| 15 | Test the ignition 3 voltage circuit for an open or for a high resistance between S204 and the multifunction switch. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 24 | |
| 16 | Test the cruise control set/coast switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 24 | |
| 17 | Test the cruise control resume/accel switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 24 | |
| 18 | Test the cruise control engaged signal circuit for an open, for a high resistance, or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 23 | |
| 19 | Repair the open, the high resistance, or the short to ground in the stop lamp supply voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 29 | ||
| 20 | Repair the open or the high resistance in the vehicle speed signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 29 | ||
| 21 | Repair the open, the high resistance, or the short to ground in the ignition 3 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 29 | ||
| 22 | Repair the open or the high resistance in the ground circuit of the cruise control module. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 29 | ||
| 23 | Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 26 | |
| 24 | Inspect for poor connections at the harness connector of the multifunction switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 27 | |
| 25 | Inspect for poor connections at the harness connector of the cruise control module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 29 | Go to Step 28 | |
| 26 | IMPORTANT: Program the replacement PCM. Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls - 4.3L.Did you complete the replacement? | Go to Step 29 | ||
| 27 | Replace the multifunction switch. Refer to Multifunction, Turn Signal Switch Replacement in Steering Wheel and Column. Did you complete the replacement? | Go to Step 29 | ||
| 28 | Replace the cruise control module. Refer to Cruise Control Module Replacement (4.3L Engine) . Did you complete the replacement? | Go to Step 29 | ||
| 29 | Operate the vehicle within the conditions for cruise control operation. Does the cruise control system operate correctly? | System OK | Go to Step 2 | |
| IMPORTANT |
|---|
| Program the replacement PCM. |
Cruise Control Inoperative/Malfunctioning (4.3L)
- The vehicle speed is greater than 40 km/h (25 mph).
- The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear.
- The system voltage is within 12-16 volts.
- The vehicle speed is greater than 40 km/h (25 mph).
- The vehicle is not in PARK, REVERSE, NEUTRAL, or 1st gear.
- The system voltage is between 12 volts and 16 volts.
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Cruise Control Schematics Connector End View Reference: Cruise Control Connector End Views or Engine Control Module (ECM) Connector End Views in Engine Controls - 6.6L (LB7) or to Engine Control Module (ECM) Connector End Views in Engine Controls - 6.6L (LLY) | |||
| 1 | Did you perform the Cruise Control Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Cruise Control |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. Turn the cruise control On/Off switch OFF. With the scan tool, observe the Cruise On/Off Switch parameter in the PCM Engine Data 1 data list. Does the Cruise On/Off Switch parameter display Off? | Go to Step 3 | Go to Step 6 |
| 3 | Turn the cruise control On/Off switch ON. With the scan tool, observe the Cruise On/Off Switch parameter. Does the Cruise On/Off Switch parameter display On? | Go to Step 4 | Go to Step 10 |
| 4 | With the scan tool, observe the Cruise Set/Coast Switch parameter in the PCM Engine Data 1 data list. Turn the cruise control On/Off switch ON. Press and hold the cruise control Set/Coast switch. Does the Cruise Set/Coast Switch parameter display On? | Go to Step 5 | Go to Step 7 |
| 5 | With the scan tool, observe the Cruise Resume/Accel. Switch parameter in the PCM data list. Press and hold the Resume/Accel switch. Does the Cruise Resume/Accel. Switch parameter display On? | Go to Step 9 | Go to Step 8 |
| 6 | Turn OFF the ignition. Disconnect the cruise control switch. Turn ON the ignition, with the engine OFF. Connect a test lamp between the cruise control on switch signal circuit and a good ground. Does the test lamp illuminate? | Go to Step 11 | Go to Step 20 |
| 7 | Turn OFF the ignition. Disconnect the cruise control switch. Turn ON the ignition, with the engine OFF. Connect a 3 ampere fused jumper between the cruise control set/coast switch signal circuit and the ignition 3 voltage circuit. With the scan tool, observe the Cruise Set/Coast Switch parameter. Does the Cruise Set/Coast Switch parameter display On? | Go to Step 20 | Go to Step 15 |
| 8 | Turn OFF the ignition. Disconnect the cruise control switch. Turn ON the ignition, with the engine OFF. Connect a 3 ampere fused jumper between the cruise control resume/accel switch signal circuit and the ignition 3 voltage circuit. With the scan tool, observe the Cruise Resume/Accel. Switch parameter. Does the Cruise Resume/Accel. Switch parameter display On? | Go to Step 20 | Go to Step 16 |
| 9 | With the scan tool, observe the TCC Cruise Brake Pedal parameter in the PCM Engine Data 1 data list. Depress the brake pedal. Does the TCC Cruise Brake Pedal parameter display Applied? | Go to Diagnostic Aids | Go to Step 17 |
| 10 | Turn OFF the ignition. Disconnect the cruise control switch. Turn ON the ignition, with the engine OFF. Connect a test lamp between the ignition 3 voltage circuit and a good ground. Does the test lamp illuminate? | Go to Step 12 | Go to Step 18 |
| 11 | Test the cruise control on switch signal circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 21 |
| 12 | Test the cruise control on switch signal circuit for an open, for a high resistance or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 13 |
| 13 | Test the cruise control resume/accel switch signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 14 |
| 14 | Test the cruise control set/coast switch signal circuit for a for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 20 |
| 15 | Test the cruise control set/coast switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 21 |
| 16 | Test the cruise control resume/accel switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 21 |
| 17 | Test the TCC/Brake switch signal circuit for an open, for a high resistance, or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 19 |
| 18 | Repair the open, the high resistance, or the short to ground in the ignition 3 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 25 | |
| 19 | Inspect for poor connections at the harness connector of the stop lamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 22 |
| 20 | Inspect for poor connections at the harness connector of the cruise control switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 23 |
| 21 | Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 25 | Go to Step 24 |
| 22 | Replace the stop lamp switch. Refer to Stop Lamp Switch Replacement in Lighting Systems. Did you complete the replacement? | Go to Step 25 | |
| 23 | Replace the multifunction turn signal lever. Refer to Multifunction, Turn Signal Switch Replacement in Steering Wheel and Column. Did you complete the replacement? | Go to Step 25 | |
| 24 | IMPORTANT: Program the replacement ECM. Replace the ECM. Refer to Engine Control Module (ECM) Replacement in Engine Controls - 6.6L (LB7) or to Engine Control Module (ECM) Replacement in Engine Controls - 6.6L (LLY).Did you complete the replacement? | Go to Step 25 | |
| 25 | Operate the vehicle within the conditions for cruise control operation. Does the cruise control system operate properly? | System OK | Go to Step 2 |
| IMPORTANT |
|---|
| Program the replacement ECM. |
Cruise Control Inoperative/Malfunctioning (6.6L)
Cruise Control Engaged
The cruise control system will engage and adjust 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 cruise control module monitors the signal circuits of the cruise control switches in order to determine when to capture and maintain the selected vehicle speed. The cruise control module receives the vehicle speed signal from the PCM, via the vehicle speed signal circuit. The cruise control module is an electronic controller and an electric stepper motor. The electric controller monitors the vehicle speed and operates the electric stepper motor. The electric stepper motor moves a strap that is attached to the cruise control cable in order to move the throttle linkage.
Ignition positive voltage is supplied from the 10-ampere CRUISE fuse, to the cruise control switch and to the cruise control module via the ignition 3 voltage circuit. When the normally open cruise control On/Off switch is turned On, the switch closes and the cruise control module detects a high signal voltage on the cruise on switch signal circuit. When the normally open Set/Coast switched is pressed, the switch closes and the cruise control module detects a high signal voltage on the set/coast signal circuit. To engage the cruise control system, the On/Off switch must be On and the Set button momentarily pressed. The cruise control module grounds the cruise control engaged signal circuit to the PCM. The PCM will confirm that the cruise control enable criteria has been met. The cruise control module will 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 cruise control module 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 cruise control module 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 cruise control module 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 cruise control module.
Cruise Control Disengaged
The cruise control module disengages the cruise control operation based on the signals from the following switches
- The On/Off switch
- The CCP switch
- The stop lamp switch
- The TCC brake switch
The stop lamp switch, the TCC brake switch, and the CPP switch are used to disengage the cruise control system. The stop lamp and the TCC brake switch are incorporated into an assembly and are mounted to the brake pedal bracket. When the brake pedal is depressed, the normally open stop lamp switch closes and the normally closed TCC brake switch opens. The cruise control module detects a high signal voltage on the stop lamp switch signal circuit and a low signal voltage on the TCC brake switch/cruise control release signal circuit. Depressing the clutch pedal while the cruise control is engaged will disengaged the cruise control system. When the clutch pedal is depressed, the normally closed CPP switch opens and the cruise control module detects a low signal voltage on the CCP switch signal circuit. The vehicle speed stored in the memory of the cruise control module will be erased when the cruise control On/Off switch is turned Off, or the ignition switch is turned off.
When the cruise control system is disengaged, the PCM sends a class 2 message to the IPC in order to deactivate the cruise control indicator.
Cruise Control Inhibited
The cruise control module assembly contains a low speed limit which will prevent system engagement below a minimum speed of 40 km/h (25 mph).
The cruise control will not engage if the cruise control module detects a low voltage signal on the CHMSL supply voltage/stop lamp supply voltage circuit when the brake pedal is depressed.
The throttle actuator control (TAC) module monitors the signal circuits of the following cruise control switches
- On/Off
- Resume/Accel
- Set/Coast
The powertrain control module (PCM) will engage and adjust vehicle speed based on the information received from the TAC module via the UART serial data link. For further information on the TAC System, refer to Throttle Actuator Control (TAC) System Description in Engine Controls - 4.8L, 5.3L, and 6.0L or to Throttle Actuator Control (TAC) System Description in Engine Controls - 8.1L.
The cruise control switches are located on the multifunction/turn signal lever.
Ignition positive voltage is supplied from the 10-ampere CRUISE 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 TAC module 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 TAC module 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 TAC module sends a UART message to the PCM, in order to confirm that the cruise control enable criteria has been met. 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 TAC module 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.
The powertrain control module (PCM) disengages the cruise control operation based on the information received from the throttle actuator control (TAC) module. The TAC module monitors the signal circuits of the following switches
- The On/Off switch
- The torque converter clutch (TCC)/brake switch
- The stop lamp switch
- The clutch pedal position (CPP) switch
The TCC brake switch and the stop lamp switch are incorporated into an assembly and are mounted to the brake pedal bracket. Pressing the brake pedal while the cruise control is engaged will disengaged the Cruise Control System. The TAC module monitors the stop lamp switch signal circuit and the PCM monitors the TCC brake switch/cruise control release signal circuit. When the brake pedal is pressed, the normally closed TCC brake switch opens and the normally open stoplamp switch closes. The TAC module detects a high signal voltage on the stop lamp switch signal circuit and the PCM detects a low signal voltage on the TCC brake switch/cruise control release signal circuit. The TAC module sends a UART message to the PCM indicating the status of the stop lamp switch. The CPP switch is mounted to the clutch pedal bracket. Depressing the clutch pedal while the cruise control is engaged will disengaged the Cruise Control System. When the clutch pedal is depressed, the normally closed clutch switch closes and the PCM detects a low signal voltage on the clutch pedal position switch signal circuit. The Cruise Control System will disengage when the cruise control On/Off switch is turned Off. The vehicle speed stored in the memory of the PCM will be erased when the cruise control On/Off switch is turned to Off, or the ignition switch is turned OFF.
The Cruise Control System will disengage when the PCM detects that the driver has the accelerator pedal override active for approximately 60 seconds.
When the Cruise Control System is disengaged, the PCM sends a class 2 message to the instrument panel cluster (IPC) in order to deactivate the cruise control indicator.
The powertrain control module (PCM) inhibits the cruise control operation when any of the following conditions exist
- A Cruise Control System related DTC has been set.
- The vehicle speed is less than 40 km/h (25 mph).
- The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear.
- The engine RPM low.
- The engine RPM is high.
- The vehicle speed is to high.
- The system voltage is not between 6-16 volts.
- The Antilock Brake System (ABS)/Traction Control System (TCS) is active for more than 2 seconds.
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 ECM monitors the signal circuits of the cruise control switches in order to determine when to capture and maintain the selected vehicle speed.
Ignition positive voltage is supplied from the 10-ampere CRUISE 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 ECM 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 ECM 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 ECM will confirm that the cruise control enable criteria has been achieved. The ECM will engage the cruise control system and record the selected vehicle speed. The ECM 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 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/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 ECM 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 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 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 ECM.
The ECM disengages the cruise control operation based on the signals from the following switches
- The On/Off switch
- The TCC brake switch
- The stop lamp switch
- The CPP switch
The TCC brake switch and the stop lamp switch are incorporated into an assembly and are mounted to the brake pedal bracket. Pressing the brake pedal while the cruise control is engaged will disengaged the cruise control system. The ECM monitors the TCC brake switch/cruise control release signal circuit and the stoplamp switch signal circuit. When the brake pedal is pressed, the normally closed TCC brake switch opens and the normally open stoplamp switch closes. The ECM detects a low signal voltage on the TCC brake switch/cruise control release signal circuit and detects a high signal voltage on the stop lamp switch signal circuit. Depressing the clutch pedal while the cruise control is engaged will disengaged the cruise control system. When the clutch pedal is depressed, the normally closed CPP switch opens and the ECM detects a low signal voltage on the CPP switch signal circuit. The cruise control system will disengage when the cruise control On/Off switch is turned Off. The vehicle speed stored in the memory of the ECM will be erased when the cruise control On/Off switch is turned to Off, or the ignition switch is turned off.
The cruise control system will disengage when the ECM detects that the driver has the accelerator pedal override active for approximately 60 seconds.
When the cruise control system is disengaged, the ECM sends a class 2 message to the IPC in order to deactivate the cruise control indicator.
The ECM inhibits the cruise control operation when any of the following conditions exist
- A cruise control system related DTC has been set.
- The vehicle speed is less than 40 km/h (25 mph).
- The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear.
- The engine RPM low.
- The engine RPM is high.
- The vehicle speed is to high.
- The system voltage is not between 6 volts and 16 volts.
- The antilock brake system/traction control system is active for more than 2 seconds.