Pinpoint Test A: The Cruise Control Is Inoperative
Cruise Control
Pinpoint Tests
Pinpoint Test A: The Cruise Control Is Inoperative
Normal Operation
The cruise control switches, which are integral to the LH steering wheel switch, use the Steering Column Control Module (SCCM) RUN/START voltage and the SCCM ground. The cruise control functionality is controlled through the cruise control switches, which are hardwired to the SCCM through signal and return circuits.
There are 4 cruise control switches with each switch operating a specific function that uses different resistance values. The SCCM sends out a reference voltage to the cruise control switches and monitors the voltage drop when a cruise control switch is pressed. The voltage drop varies depending upon the resistance of each switch, providing a specific indication to the SCCM of which switch is pressed. The SCCM sends a network message over the High Speed Controller Area Network (HS-CAN) to the PCM activating and controlling the cruise control system.
The stoplamp switch is a single plunger 2-stage switch with 2 inputs to the PCM. When the brake pedal is applied, the first stage, which is a normally open stoplamp switch, closes and sends a voltage signal to the PCM deactivating the cruise control, if engaged. The second stage is the normally closed cruise control deactivator switch (integral to the stoplamp switch), which opens and removes the ground signal to the PCM when the brake pedal is firmly applied. This is a redundant signal to the PCM. There is less than one millimeter in plunger travel between the first and second stage.
This pinpoint test is intended to diagnose the following:
- PCM not configured for cruise control
- Cruise control switches (part of the LH steering wheel switch)
- Stoplamp switch
- Cruise control deactivator switch (integral to the stoplamp switch)
- Digital Transmission Range (TR) sensor
- PCM
- SCCM
- ABS fault
PINPOINT TEST A: THE CRUISE CONTROL IS INOPERATIVE
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A1 CHECK FOR DTCs
- Review the recorded DTCs from the PCM and SCCM self-test.
- Are any DTCs recorded?
Yes
REFER to DTC Charts. Diagnostic Trouble Code Tests and Associated Procedures
No
GO to A2.
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A2 CHECK FOR ABS MODULE DTCs
- Review the recorded DTCs from the ABS module self-test.
- Are any DTCs recorded?
Yes
REFER to Vehicle Dynamic Systems Testing and Inspection. REPAIR all ABS module DTCs and RETEST the system.
No
GO to A3.
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A3 CHECK THE STOPLAMP SWITCH (BOO1) AND CRUISE CONTROL DEACTIVATOR SWITCH (BOO2) PIDs
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM PIDs BOO1 (stoplamp switch) and BOO2 (cruise control deactivator switch) while applying and releasing the brake pedal as follows:
- Do the PID values agree with the brake pedal position?
Yes
For gasoline engine, GO to A4.
For diesel engine, GO to A5.
No
GO to Pinpoint Test B. Pinpoint Test B: DTC P0504, P0572, P0573 Or P1703
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A4 MONITOR THE PCM 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 TR selector lever position?
Yes
GO to A5.
No
For 6.8L engine, REFER to Automatic Transaxle/Transmission - TorqShift(R) Testing and Inspection to continue diagnosis of the digital TR sensor.
For 6.2L engine, REFER to Automatic Transaxle/Transmission - TorqShift(R)6 Testing and Inspection to continue diagnosis of the digital TR sensor.
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A5 MONITOR THE TRANSMISSION CONTROL MODULE (TCM) TR PID
- Enter the following diagnostic mode on the scan tool: TCM DataLogger.
- Monitor the PCM PID (TR).
- Select DRIVE.
- Does the PID value agree with the TR selector lever position?
Yes
GO to A6.
No
REFER to Automatic Transaxle/Transmission - TorqShift(R)6 Testing and Inspection to continue diagnosis of the digital TR sensor.
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A6 CHECK THE CRUISE CONTROL SWITCH
- Enter the following diagnostic mode on the scan tool: SCCM 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 A7.
No
If only one switch does not display the correct PID value, INSTALL a new LH steering wheel switch. REFER to Steering Column Switches Steering Wheel 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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A7 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 Powertrain Control Module (PCM).
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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