Pinpoint Test A: The Cruise Control Is Inoperative
Cruise Control
Pinpoint Test A: The Cruise Control Is Inoperative
Normal Operation
For all cruise control systems, the cruise control switches, which are integral to the message center 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 3 toggle momentary contact 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 relaying the switch status and requesting cruise control operation.
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.
On vehicles with the adaptive cruise control system, the Cruise-Control Module (C-CM) communicates with the Instrument Panel Cluster (IPC), Body Control Module (BCM), Head Up Display (HUD) module, Restraints Control Module (RCM), ABS module and PCM over the High Speed Controller Area Network (HS-CAN). Through the module network communication the C-CM (Cruise-Control Module) controls the adaptive cruise control system.
This pinpoint test is intended to diagnose the following:
- Cruise control switches (part of the message center switch)
- Cruise control deactivator switch (integral to the stoplamp switch)
- Digital Transmission Range (TR) sensor
- PCM
- Stoplamp switch
- Vehicle speed signal
- ABS module (with adaptive cruise control)
- BCM (Body Control Module) (with adaptive cruise control)
- C-CM (Cruise-Control Module) (with adaptive cruise control)
- SCCM (Steering Column Control Module)
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
If the vehicle is equipped with adaptive cruise control, GO to A2. Otherwise, GO to A5.
A2 CHECK THE C-CM (Cruise-Control Module) DTCs
- Review the recorded DTCs from the C-CM (Cruise-Control Module) self-test.
Are any C-CM (Cruise-Control Module) DTCs recorded?
Yes
REFER to DTC Charts. Cruise Control
No
GO to A3.
A3 CHECK FOR LOST COMMUNICATION DTCs
- Ignition ON.
- Clear continuous DTCs from all modules.
- Ignition OFF.
- Ignition ON.
- Wait at least 10 seconds.
- Retrieve all continuous DTCs from all modules.
Are any lost communication DTCs set in the C-CM (Cruise-Control Module) module?
Yes
REFER to DTC Charts. Cruise Control
No
GO to A4.
A4 CHECK FOR ABS MODULE AND BCM (Body Control Module) DTCs
- Review the recorded DTCs from the ABS module and BCM (Body Control Module) self-test.
Are any DTCs recorded?
Yes
REFER to DTC Charts. Cruise Control
No
GO to A5.
A5 CHECK THE STOPLAMP SWITCH (BOO1) AND CRUISE CONTROL DEACTIVATOR SWITCH (BOO2) PIDs
- Enter the following diagnostic mode on the scan tool: Powertrain DataLogger- Cruise Control.
- Monitor the powertrain 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 A6.
No
GO to Pinpoint Test B. Pinpoint Test B: DTC P0504, P0572, P0573 Or P1703
A6 CHECK THE CRUISE CONTROL SWITCH
- Enter the following diagnostic mode on the scan tool: Powertrain DataLogger- Cruise Control.
- Press each cruise control switch while monitoring the cruise control switch PID (SCCS).
Cruise Control Switches - Without Adaptive Cruise
Cruise Control Switch SCCS PID Value- None Pressed RES RESUME CNCL CANCEL ON/OFF (pressed up) On ON/OFF (pressed down) Off SET (pressed up) SET/+ SET (pressed down) SET/-
Cruise Control Switches - With Adaptive Cruise
Cruise Control Switch SCCS PID Value- None Pressed RES/CNCL RESUME/CANCEL ON/OFF On/Off SET (pressed up) SET/+ SET (pressed down) SET/- GAP (pressed up) GAP- GAP (pressed down) GAP+
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 Switch Is Inoperative/Does Not Operate Correctly
A7 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 A8.
No
REFER to Automatic Transmission/Transaxle &/or Transmission Control Systems to continue diagnosis of the digital TR (Transmission Range) sensor.
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. 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.