Cruise Control Input Test

NOTE: Always make sure that you have the latest HDS software.

Connect the HDS to the DLC (see step 2 on GENERAL TROUBLESHOOTING INFORMATION ).
Turn the ignition switch to ON (II).
Make sure the HDS communicates with the vehicle and the PCM. If it does not communicate, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
Check for and troubleshoot any DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).
Do the following tests while monitoring parameters in the PGM-FI DATA LIST with the HDS.

If the input tests prove OK, replace the PCM (see PCM REPLACEMENT ).

NOTE: Intermittent failures are often caused by loose circuit connections. While monitoring cruise control inputs, flex the circuits wires, and note if any of the test results change.

Signal to be tested	Test condition	Parameter: Desired result	Possible cause if result is not obtained
Idle stop position switch signal	Brake pedal pressed, then released	CRUISE BRAKE SW/IDLE STOP SW should indicate OPEN when the brake pedal is pressed and CLOSE when the brake pedal is released.	Faulty idle stop switch Blown No. 12 (10 A) fuse in the under-dash fuse/relay box An open in the wire between the PCM and the idle stop switch A wire shorted to ground between the PCM and the idle stop switch
Cruise control main switch signal	Cruise control main button ON and OFF	CRUISE MASTER (MAIN) SW should indicate ON when the cruise control main button is pressed and OFF when the cruise control main button is released.	Faulty cruise control combination switch An open in the wire between the gauge control module and the cruise control combination switch A wire shorted to ground between the gauge control module and the cruise control combination switch An open in the wire between the cruise control combination switch and ground G502, G551
Set switch signal	Decel/set button pressed and released	CRUISE SET SW should indicate ON when the decel/set button is pressed and OFF when the decel/set button is released.	Faulty cruise control combination switch An open in the wire between the gauge control module and the cruise control combination switch A wire shorted to ground between the gauge control module and the cruise control combination switch
Resume switch signal	Resume/accel button pressed and released	CRUISE RESUME SW should indicate ON when the resume/accel button is pressed and OFF when the resume/accel button is released.	Faulty cruise control combination switch An open in the wire between the gauge control module and the cruise control combination switch A wire shorted to ground between the gauge control module and the cruise control combination switch
Cancel switch signal	Cancel button pressed and released	CRUISE CANCEL SW should indicate ON when the cancel button is pressed and OFF when the cancel button is released.	Faulty cruise control combination switch An open in the wire between the gauge control module and the cruise control combination switch A wire shorted to ground between the gauge control module and the cruise control combination switch.
Cruise control indicator signal	Start the engine, press the cruise control main button on, and drive the vehicle above 25 mph (40 km/h), with cruise control set and cancel the cruise control.	CRUISE INDICATOR should indicate ON when the cruise control is set and OFF when the cruise control is canceled.	Faulty gauge control module Faulty cruise control combination switch An open in the wire between the gauge control module and the cruise control combination switch A wire shorted to ground between the gauge control module and the cruise control combination switch.