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, voltage is routed through a specific resistor value for each function. The PCM provides ground for the reference voltage to determine which control input function has been selected. When the brake pedal is firmly applied, the PCM deactivates the cruise control, if engaged.
The cruise control deactivator switch (integral to the stoplamp switch) removes the voltage signal to the PCM when the brake pedal is firmly applied. This is a redundant signal to the PCM.
The ABS module monitors brake pressure and also receives a voltage signal from the stoplamp switch. A fault in the ABS module can disable the cruise control system.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- PCM not configured for cruise control
- Stoplamp switch
- Cruise control switch
- Cruise control deactivator switch (integral to the stoplamp switch)
- Digital Transmission Range (TR) sensor
- Vehicle speed signal
- PCM
- ABS module
PINPOINT TEST A: THE CRUISE CONTROL IS INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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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 Antilock Brakes / Traction Control Systems. REPAIR all ABS module DTCs and RETEST the system.
No
GO to A3.
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A3 CHECK FOR PCM DTCs
- Review the recorded DTCs from the PCM self-test.
- Are any non-cruise control DTCs recorded?
Yes
REFER to Computers and Control Systems Information. REPAIR all PCM DTCs and RETEST the system.
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 Instrument Panel, Gauges and Warning Indicators to continue diagnosis of the speedometer.
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A5 CHECK THE STOPLAMP SWITCH (BOO AND BPA) PIDs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PIDs BOO (brake pedal top travel) and BPA (brake pedal bottom travel) while applying and releasing the brake pedal as follows:
- Do the PID values agree with the brake pedal positions?
Yes
GO to A6.
No
GO to Pinpoint Test B. Pinpoint Test B: DTC P1572 Or DTC P1703
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A6 MONITOR THE PCM (TR) PID
- Apply the parking brake.
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PID (TR).
- Select DRIVE.
- Does the PID value agree with the transmission range selector lever position?
Yes
GO to A7.
No
REFER to Automatic Transmission/Transaxle &/or Transmission Control Systems to diagnose the digital Transmission Range (TR) sensor.
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A7 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 A8.
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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A8 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 Computers and Control Systems. 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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