Important: Review the system operation in order to familiarize yourself with the system
functions.
Refer to
Cruise Control Description and Operation
.
Visual/Physical Inspection
When a vehicle is suspected of having a cruise control system operation malfunction,
it is important to carry out the following preliminary diagnosis. This diagnoses should
be used to determine whether the cruise control system problem is the result of an
actual system defect, or the result of a problem with some other vehicle component.
Also, some cruise control system complaints may be a misunderstanding by the
driver about how the cruise control system functions. In that case the operation of
the system should be explained in a manner the driver understands. A practical demonstration
is very useful to explain system operation.
If it is decided that the cruise control system is at fault, perform a visual
inspection of all components in the system. Cruise control malfunctions can be caused
by mechanical, electrical, or a combination of both problems.
Things to inspect are:
| • | Inspect for aftermarket devices which could affect the operation of the
Cruise Control System. |
| • | Inspect the easily accessible or visible system components for obvious
damage or conditions which could cause the symptom. |
| • | Switch inputs to the cruise control module |
| • | Dirty, loose, or corroded electrical connectors |
| • | Damaged or incorrectly adjusted stop lamp switch |
| • | Damaged or incorrectly adjusted electrical release switch |
| • | Damaged or incorrectly adjusted clutch switches |
| • | Binding or sticky throttle linkage |
| • | Broken components e.g. cruise control cable |
| • | Bare, broken or disconnected wires |
| • | Cruise control cable adjustment |
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions.
Refer to
Testing for Intermittent Conditions and Poor Connections
in Wiring Systems.
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to
diagnose the symptom:
Cruise Control Inoperative/Malfunctioning
