Pinpoint Test A: The Cruise Control Is Inoperative
Cruise Control
Pinpoint Tests
Pinpoint Test A: The Cruise Control Is Inoperative
Refer to Wiring Diagram Set 31, Cruise Control for schematic and connector information. Diagrams By Number
Normal Operation
A reference voltage is sent from the PCM to the steering wheel cruise control switches. When a switch is pressed, the voltage is routed through a specific resistor value for each function. The PCM provides the ground for the reference voltage to determine which control input function has been selected. When the brake pedal is applied the PCM deactivates the cruise control if engaged.
The ABS module monitors brake pressure and the stoplamp switch signal from the stoplamp switch. A fault in the ABS module can disable the cruise control system.
The cruise control deactivator switch interrupts the voltage signal to the PCM when the brake pedal is applied. This is a redundant signal to the PCM.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- PCM not configured for cruise control
- Stoplamp switch
- Cruise control deactivator switch (integral to the stoplamp switch)
- Cruise control switches
- Digital Transmission Range (TR) sensor
- Vehicle speed signal
- PCM
- ABS module
- Park brake
PINPOINT TEST A: THE CRUISE CONTROL IS INOPERATIVE
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A1 VERIFY PCM CONFIGURATION
- Enter the following diagnostic mode on the scan tool: Programmable Parameters.
- Verify that the cruise control is enabled in the PCM.
- Is the cruise control enabled?
Yes
GO to A2.
No
ENABLE the cruise control in the PCM using the scan tool programmable parameters menu. TEST the system for normal operation.
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A2 CHECK FOR ABS DTCs
- Review the recorded DTCs from the ABS self-test.
- Are any DTCs recorded?
Yes
REFER to the Vehicle Dynamic Systems Testing and Inspection. REPAIR all ABS module DTCs and RETEST the cruise control.
No
GO to A3.
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A3 CHECK FOR PCM DTCs
- Review the recorded DTCs from the PCM self-test.
- Are any DTCs present?
Yes
For cruise control DTCs, REFER to DTC Charts. Diagnostic Trouble Code Tests and Associated Procedures
For non-cruise control DTCs, REFER to Computers and Control Systems. REPAIR all PCM DTCs and RETEST the cruise control.
No
GO to A4.
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A4 CHECK THE VEHICLE SPEED
- Check for correct operation of the speedometer.
- Does the speedometer operate correctly?
Yes
GO to A5.
No
REFER to Instrumentation, Message Center, and Warning Chimes Testing and Inspection to continue diagnosis of the speedometer.
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A5 CHECK THE PARK BRAKE
- Monitor the park brake indicator while applying and releasing the park brake.
- Does the park brake operate correctly?
Yes
GO to A6.
No
REFER to Instrumentation, Message Center, and Warning Chimes Testing and Inspection to continue diagnosis of the park brake.
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A6 CHECK THE STOPLAMP SWITCH (BOO1 AND BOO2) PIDs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PIDs BOO1 (brake pedal top travel) and BOO2 (brake pedal bottom travel) while applying and releasing the brake pedal as follows:
- Do the PID values agree with the brake pedal position?
Yes
If equipped with a floor shift, GO to A7.
If equipped with a column shift, GO to A8.
No
GO to Pinpoint Test B. Pinpoint Test B: DTC P1703 Or DTC P1572
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A7 MONITOR THE TCM (TR) PID
- Enter the following diagnostic mode on the scan tool: TCM DataLogger.
- Monitor the TCM transmission range PID (TR).
- Select DRIVE.
- Does the PID value agree with the TR selector lever position?
Yes
GO to A9.
No
REFER to Automatic Transaxle/Transmission - 6R80 Testing and Inspection to continue diagnosis of the digital TR sensor.
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A8 MONITOR THE PRNDL DISPLAY
- Monitor the PRNDL display in the Instrument Cluster (IC).
- Select DRIVE.
- Does the PRNDL display agree with the TR selector lever position?
Yes
GO to A9.
No
REFER to Instrumentation, Message Center, and Warning Chimes Testing and Inspection to continue diagnosis of the PRNDL display.
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A9 CHECK THE CRUISE CONTROL SWITCH
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Press each cruise control switch while monitoring the cruise control switch PID (SCCS).
- Does the PID value agree with the switch position?
Yes
GO to A10.
No
If only one switch does not display the correct PID value, INSTALL a new cruise control switch. REFER to Cruise Control Switch Service and Repair. TEST the system for normal operation.
Otherwise, GO to Pinpoint Test C. Pinpoint Test C: The Cruise Control Switches Do Not Operate Correctly
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A10 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the PCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new PCM. REFER to Electronic Engine Controls Service and Repair. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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