Important:
- Perform the
Diagnostic System Check
| • | The control module(s) can communicate via the serial data link. |
- Review the system operation in order to
familiarize yourself with the system functions. Refer to
Transfer Case Circuit Description
and
Transfer Case Description
Visual/Physical Inspection
| • | Inspect for aftermarket devices which could affect the operation
of the Manual Selectable 4 Wheel Drive System. Refer to
Checking Aftermarket Accessories
in Wiring Systems. |
| • | Inspect the easily accessible or visible system components for
obvious damage or conditions which could cause the symptom. |
| • | Ensure all mechanical components are operative before diagnosing
the electrical portion of the system. |
| • | In order to determine whether the vehicle is in two-wheel drive
or four-wheel drive, lift the vehicle so that the wheels can spin freely.
Turning the rear drive shaft and the front drive shaft turns with the front,
the vehicle is in 4WD. |
| • | Make sure that the 4WD fuse is not open. If open, locate and
repair the source of the overload. Refer to
Testing for Short to Ground
in wiring systems. Replace the fuse. |
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:
