Pinpoint Test A: The Cruise Control Is Inoperative
Cruise Control
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.
When the brake pedal is applied, the ABS module receives the stoplamp signal and sends a message over the High Speed Controller Area Network (HS-CAN) to the PCM to deactivate the cruise control, if engaged. The cruise control deactivator switch removes the voltage signal to the PCM when the brake pedal is applied firmly. 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
- Cruise control switches
- Stoplamp signal concern
- Digital Transmission Range (TR) sensor
- Vehicle speed signal
- PCM
- ABS module
PINPOINT TEST A: THE CRUISE CONTROL IS INOPERATIVE
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A1 VERIFY THE 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 DTCs
- Check for recorded PCM DTCs from the continuous and Key ON Engine OFF (KOEO) on-demand self-tests.
- Are any DTCs recorded?
Yes
REFER to DTC Charts. [1][2]Diagnostic Trouble Code Descriptions
No
GO to A3.
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A3 CHECK THE STOPLAMP SWITCH INPUT TO THE PCM
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PID BOO while applying and releasing the brake pedal.
- Do the PIDs agree with the stoplamp switch position?
Yes
GO to A4.
No
REFER to Vehicle Dynamic Systems Testing and Inspection to continue diagnosis of the ABS system.
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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 CRUISE CONTROL SWITCH
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Press each cruise control switch button while monitoring the cruise control switch PID SCCS.
- Does the PID value agree with the switch position?
Yes
GO to A6.
No
If only one switch does not display the correct PID value, INSTALL a new cruise control switch. REFER to Cruise Control Switch Cruise Control Switch. 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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A6 MONITOR THE TR PID
- 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 Transaxle/Transmission - 4R70E/4R75E Testing and Inspection to continue diagnosis of the digital TR sensor.
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A7 CHECK THE CRUISE CONTROL DEACTIVATOR SWITCH FOR CORRECT OPERATION
- Ignition OFF.
- Disconnect: PCM C175b.
- While firmly applying and releasing the brake pedal, measure the voltage between the PCM C175b-9, circuit 636 (OG), harness side and ground.
- Is the voltage greater than 10 volts with the brake pedal released and 0 volts with the brake pedal firmly applied?
Yes
GO to A8.
No
GO to Pinpoint Test B. Pinpoint Test B: DTC P1572 Or DTC P1703
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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 are seated 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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