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 to the PCM over the High Speed Controller Area Network (HS-CAN), 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.
The PCM has cruise control deactivation event PIDs available, through the powertrain datalogger, that show what caused the cruise control deactivation during the current key cycle. Refer to Cruise Control Deactivation Event PIDs.
This pinpoint test is intended to diagnose the following:
- 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 BOO2) PIDs
- Ignition ON.
- 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
GO to A4.
No
GO to Pinpoint Test B. Pinpoint Test B: DTC P0504:00, P0572:00, P0573:00 Or P1703:00
A4 MONITOR THE PRNDL DISPLAY
- Monitor the PRNDL display in the Instrument Panel Cluster (IPC).
- Select DRIVE.
Does the PRNDL display agree with the TR (Transmission Range) selector lever position?
Yes
GO to A5.
No
REFER to Instrument Panel, Gauges and Warning Indicators, to continue diagnosis of the PRNDL display.
A5 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 button while monitoring the cruise control switch PID (SCCS).
Cruise Control Switch SCCS PID Value- NONE Pressed CNCL/RSM 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 A6.
No
If only one switch does not display the correct PID value, INSTALL a new 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
A6 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. 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.