P0591-00

P0591-00-SPEED CONTROL SWITCH 2 PERFORMANCE

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Right Steering Wheel Control Switch (Speed Control Switch) includes the cruise control functions. Cruise Control Functions are resistor multiplexed and are hard wired inputs to the Steering Angle Sensor (SAS) microprocessor. The switch also contains the circuitry of a Local Interface Network (LIN) slave node, which provides source current for and communicates the switch or sensor states of the Electronic Vehicle Information Center (EVIC) switches, the remote radio switches and the horn switch over the LIN data bus to the SAS, which is also the LIN master node and a gateway to the Controller Area Network (CAN) data bus. Speed Control Switch - Operation

- When Monitored:
Continuously with the ignition on.

- Set Condition:
The Steering Column Control Module (SCCM) has detected that a non-permissible combination has occurred in the Speed Control Switch.





1. CHECK FOR AN ACTIVE DTC

NOTE: Before proceeding with the diagnostic procedure, verify that the connections are properly made, seated and verify proper pin terminal tension. A loose connection at any of the SCCM connectors may cause the DTC to set.

1. Turn the ignition on.
2. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK THE CRUISE CONTROL INPUT 2 VOLTAGE WITH THE SCAN TOOL
1. With the scan tool, navigate to SCCM, Data Display.
2. While monitoring the Cruise Control Input 2 voltage with the scan tool, press each Speed Control switch. Compare the scan tool voltage readings with the table below.





Do the voltages displayed on the scan tool match the voltages in the table?

Yes

- Visually and physically inspect the wiring harness between the Right Steering Wheel Switch (Speed Control Switch) harness connector and the SCM C5 harness connector. Repair any damaged wires, connectors, and open/spread terminals. If harness is OK, test complete.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Right Steering Wheel Switch (Speed Control Switch). Speed Control Switch - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.