Initial Inspection and Diagnostic Overview
anti-lock Results - Self-Test PassedThe indicator lamp will flash once each time a speed control command switch is pressed during the switch sequence procedure.
After testing all cruise control switches, self-test diagnostics automatically checks for proper connection of the Brake On/Off (BOO) switch, deactivator switch, vehicle speed sensor (VSS), all motor phases, motor clutch and module internal memory. The indicator lamp will flash once if these static tests pass after the five switch sequence.
Immediately after the static test, the cruise control module then performs a dynamic test automatically by actuating the throttle lever from as little as 1 mm to a maximum of 10 mm of travel from idle position. During this throttle pull, observe throttle movement to witness any binding or sticking of actuator cable to throttle lever and assure throttle returns back to idle position. (A second person will be needed to observe throttle movement). If improper connection and/or binding or sticking of actuator is observed, go to the appropriate pinpoint test.
Visual Inspection
Visual inspection is an important part of diagnosis. Inspection should be done to locate obvious reasons for customer concerns. When performing visual inspection, check all items for abnormal conditions. Look for such items as bare, broken or disconnected wires. For the cruise control system to function properly, cruise control servo and throttle linkage should operate freely and smoothly.
Any concerns found by the visual inspection should be corrected before further tests of the system are made. The following items should be inspected.
^ ABS indicator light. If the light stays lit when the ignition switch is in RUN, refer to anti-lock brakes before continuing with cruise control diagnosis.
^ Horn. If the horn does not work, check the horn circuit fuse, horn relay and circuit wiring.
^ Stoplamps. If the stoplamps do not light with the brake pedal depressed, check the stoplamp circuit fuse, rear lamps and stoplamp switch.
^ Electronic servo assembly. Check for unseated connectors, loose or unseated connector pins and broken wires at the cruise control servo.
^ Actuator cable. Check for misadjusted or broken cruise control actuator.
Diagnostic Self-Test
The diagnostic self-test consists of a static and dynamic test and uses the cruise control indicator lamp to indicate a pass/fail of the self-test. If the static test has passed, the dynamic test will be performed automatically. Before going to a pinpoint test or component test, make sure the diagnostic self-test has been performed.
WARNING
^ This diagnostic self-test is a Key On Engine Off (KOEO) test that's only conducted in P (Park) with the parking brake fully engaged. As an option, you may lift the vehicle drive wheels off the ground during this test for complete safety even though the engine must be off during the self-test procedure.
Static Test
1. Depress the cruise control OFF switch while turning the ignition key ON. Make sure the engine does not start or is running. The cruise control indicator lamp will flash once to indicate that the cruise control module has entered the diagnostic mode.
2. Within 3 seconds after the first indicator lamp flash and pressing the OFF switch, remove finger from OFF switch and press the remaining cruise control switches in the following order:
ON
RESUME (RSM)
COAST (CST)
SET/ACCEL
If the switches are operating correctly, the indicator lamp will flash after each switch is pressed. The indicator lamp must go out before the next switch in the sequence is pressed. In addition, after OFF and ON switches are pressed, each of the remaining three switches in the sequence must be pressed within one second of the indicator lamp going out.
After all five cruise control switches complete the sequence, the indicator lamp will flash and indicate a pass or fail of the static test.
Results - Self-Test Failed
The indicator lamp will not flash if the voltage input from any switch is out of range for the switch sequence carried out previously or the lamp is defective. Also, if the sequence of pressing switches was incorrect or wasn't within the specified timing, the indicator lamp will not flash. If this is suspected, repeat the self-test switch sequence one to several times for assurance.
If the static test fails after the five switch sequence, the dynamic test will not be performed. If this is the case, the indicator lamp will flash one of the following DTCs: