Pinpoint Test A: The Cruise Control Is Inoperative
Cruise Control
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 (Steering Column Control Module) ground. The cruise control functionality is controlled through the cruise control switches, which are hardwired to the SCCM (Steering Column Control Module) 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 (Steering Column Control Module) 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 (Steering Column Control Module) of which switch is pressed. The SCCM (Steering Column Control Module) 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 (Steering Column Control Module)
- ABS fault
PINPOINT TEST A : THE CRUISE CONTROL IS INOPERATIVE
A1 CHECK FOR DTCs
- Review the recorded DTCs from the PCM and SCCM (Steering Column Control Module) self-test.
Are any DTCs recorded?
Yes
REFER to DTC Charts. Cruise Control
No
GO to A2.
A2 CHECK FOR ABS MODULE DTCs
- Review the recorded DTCs from the ABS module 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.
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:
Brake Pedal Position BOO1 PID BOO2 PID Released Off Off Applied lightly On Off Applied firmly On On
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
A4 MONITOR THE PCM TR (Transmission Range) 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 (Transmission Range) selector lever position?
Yes
GO to A5.
No
For 6.8L engine, REFER to Automatic Transmission/Transaxle &/or Transmission Control Systems to continue diagnosis of the digital TR (Transmission Range) sensor.
For 6.2L engine, REFER to Automatic Transmission/Transaxle &/or Transmission Control Systems to continue diagnosis of the digital TR (Transmission Range) sensor.
A5 MONITOR THE Transmission Control Module (TCM)
TR (Transmission Range) PID
- Enter the following diagnostic mode on the scan tool: TCM (Transmission Control Module) DataLogger.
- Monitor the PCM PID (TR).
- Select DRIVE.
Does the PID value agree with the TR (Transmission Range) selector lever position?
Yes
GO to A6.
No
To continue diagnosis of the digital TR (Transmission Range) sensor, REFER to Automatic Transmission/Transaxle &/or Transmission Control Systems.
A6 CHECK THE CRUISE CONTROL SWITCH
- Enter the following diagnostic mode on the scan tool: SCCM (Steering Column Control Module) DataLogger.
- Press each cruise control switch while monitoring the cruise control switch PID (SCCS).
Cruise Control Switch SCCS PID Value- NONE Pressed CNCL/RES RESUME/COAST ON/OFF Cruise Off or Cruise On SET + SET + SET - SET-
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. TEST the system for normal operation.
Otherwise, GO to Pinpoint Test C. Pinpoint Test C: The Cruise Control Switches Do Not Operate Correctly
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. 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.