Cruise Control (ECM/PCM) Input Test

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

2. Select PGM-FI system and check the diagnostic trouble code (DTC) and note it. Also check the on-board snapshot data, and download any data found. Then refer to the indicated DTC's troubleshooting, and begin the appropriate troubleshooting procedure.

3. If no DTCs are found, do the following tests while monitoring parameters in the DATA LIST with the HDS.If the input tests prove OK, replace the PCM

.NOTE: Intermittent failures are often caused by loose circuit connections. While monitoring cruise control inputs, flex the circuit 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
Cruise control system switch status	Cruise control combination switch buttons are not pressed	CRUISE CONTROL SYSTEM SWITCH STATUS in the HDS data list should indicate DEFAULT when the cruise control combination switch buttons are not pressed.	If the CRUISE CONTROL SYSTEM SWITCH STATUS in the HDS data list indicates SIGNAL LOST, check as shown: Check for DTCs in the PGM-FI system and do the appropriate troubleshooting. 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 short to power in the wire between the gauge control module and the cruise control combination switch when the combination light switch is turned on If the CRUISE CONTROL SYSTEM SWITCH STATUS in the HDS data list indicates SIGNAL SHORT, check as shown: Check for DTCs in the PGM-FI system and do the appropriate troubleshooting Faulty gauge control module Faulty cruise control combination switch A short to ground in the wire between the gauge control module and the cruise control combination switch If the CRUISE CONTROL SYSTEM SWITCH STATUS in the HDS data list indicates a different status, check for a faulty cruise control combination switch.
	CRUISE switch is pressed	CRUISE CONTROL SYSTEM SWITCH STATUS in the HDS data list should indicate MAIN SW when the CRUISE switch is pressed.
	CANCEL switch is pressed	CRUISE CONTROL SYSTEM SWITCH STATUS in the HDS data list should indicate CANCEL SW when the CANCEL switch is pressed.
	SET- switch is pressed	CRUISE CONTROL SYSTEM SWITCH STATUS in the HDS data list should indicate SET SW when the SET- switch is pressed.
	RES+ switch is pressed	CRUISE CONTROL SYSTEM SWITCH STATUS in the HDS data list should indicate RES SW when the RES+ switch is pressed.

Signal to be tested	Test condition	Parameter: Desired result	Possible cause if result is not obtained
Cruise control indicator signal	Start the engine, press the CRUISE button on and drive the vehicle above 25 mph (40 km/h) with the 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
Brake pedal position switch signal	Brake pedal is pressed, then released	CRUISE BRAKE SW should indicate OPEN when the brake pedal is pressed and CLOSE when the brake pedal is released.	Faulty brake pedal position switch Blown No. D21 (10 A) fuse in the under-dash fuse/relay box An open in the wire between the PCM and the brake pedal position switch A wire shorted to ground or power between the PCM and the brake pedal position switch