Pinpoint Test C: The Cruise Control Does Not Disengage When The Brakes Are Applied
Cruise Control
Pinpoint Tests
Pinpoint Test C: The Cruise Control Does Not Disengage When The Brakes Are Applied
Refer to Wiring Diagram Set 31, Speed Control for schematic and connector information. Diagrams By Number
Normal Operation
The cruise control servo monitors the stoplamp input for a ground and voltage signal. The stoplamp switch provides a ground path that enables cruise control operation when the brake pedal is released. When the brake pedal is applied, the voltage goes high and cruise control goes into stand-by mode.
Voltage for the cruise control servo clutch (internal to the cruise control actuator) is supplied by the Smart Junction Box (SJB) to the cruise control deactivator switch. The cruise control deactivator switch (closed when the brake pedal is not applied) then routes the voltage to the cruise control actuator. When the brake pedal is firmly applied, the cruise control deactivator switch opens and voltage is no longer supplied to the cruise control servo clutch.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Obstructions to the accelerator pedal or linkage
- Cruise control deactivator switch
- Stoplamp switch
- Cruise control cable
- Accelerator cable
- Cruise control actuator
PINPOINT TEST C: THE CRUISE CONTROL DOES NOT DISENGAGE WHEN THE BRAKES ARE APPLIED
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connectors.
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C1 CHECK THE CRUISE CONTROL CABLE/ACCELERATOR CABLE
- Ignition OFF.
- NOTE: Make sure the floor mat, insulation, wiring harnesses location, and other items do not interfere with the accelerator pedal and linkage.
- Visually inspect the cruise control cable connections, the throttle body linkage, and the cruise control actuator pulley cover.
- Are the cruise control cable connections, the throttle body linkage, and the cruise control cable cap cover OK?
Yes
GO to C2.
No
INSTALL a new cruise control cable or accelerator cable. For a new cruise control cable, REFER to Cruise Control Cable Service and Repair. TEST the system for normal operation. For a new accelerator cable, REFER to Acceleration Control Service and Repair. TEST the system for normal operation.
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C2 CHECK THE STOPLAMPS FOR CORRECT OPERATION
- Check the stoplamps and high mounted stoplamp for correct operation by firmly applying and releasing the brake pedal.
- Do the stoplamps operate correctly?
Yes
GO to C3.
No
REFER to Exterior Lighting Testing and Inspection to continue diagnosis of the stoplamps.
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C3 CHECK THE VOLTAGE TO THE CRUISE CONTROL DEACTIVATOR SWITCH
- Disconnect: Cruise Control Deactivator Switch C277.
- Ignition ON.
- Measure the voltage between the cruise control deactivator switch C277-1, circuit CBP26 (BU/WH) harness side and ground.
- Is the voltage greater than 10 volt?
Yes
GO to C4.
No
VERIFY the SJB fuse 26 (2A) is OK. If OK, REPAIR the circuit. TEST the system for normal operation.
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C4 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH OPERATION
NOTICE: The following step uses a test light to simulate normal circuit loads. Use only the test lamp recommended in the special tools table or equivalent. To avoid connector terminal damage, use the Rotunda Flex Probe Kit for the test light probe connection to the vehicle. Do not use the test lamp probe directly on any connector.
- Connect: Cruise Control Deactivator Switch C277.
- Disconnect: Cruise Control Actuator C122.
- Ignition ON.
- While applying and releasing the brake pedal, measure the voltage between the cruise control actuator C122-9, circuit CES09 (VT/OG), harness side and the cruise control actuator C122-10, circuit GD123 (BK/GY), harness side.
- Is the voltage greater than 10 volts with the brake pedal released and 0 volts when the brake pedal is applied?
Yes
GO to C7.
No
GO to C5.
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C5 CHECK THE CRUISE CONTROL DEACTIVATOR CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: Cruise Control Deactivator Switch C277.
- Ignition ON.
- Measure the voltage between the cruise control actuator C122-9, circuit CES09 (VT/OG), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
GO to C6.
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C6 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH SIGNAL CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between the cruise control deactivator switch C277-2, circuit CES09 (VT/OG), harness side and the cruise control actuator C122-9, circuit CES09 (VT/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new cruise control deactivator switch. REFER to Cruise Control Deactivator Switch Cruise Control Deactivator Switch. TEST the system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.
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C7 CHECK FOR CORRECT CRUISE CONTROL ACTUATOR OPERATION
- Connect: All Disconnected Connectors.
- Disconnect the cruise control actuator connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the cruise control actuator connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new cruise control actuator. REFER to Cruise Control Actuator Service and Repair. REPEAT the self-test.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation.
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