Preliminary Checks Before Starting
Important:
- Perform
Diagnostic System Check - Body Rear End
before using the symptom tables in order to verify that all of the
following are true:
| • | There are no DTCs set. |
| • | The body control module (BCM) can communicate via the serial data link. |
- Review the system description and operation in order to familiarize yourself
with the system functions. Refer to
Luggage Compartment Description and Operation
.
Visual/Physical Inspection
Several of the symptom procedures ask for a careful visual/physical check. This
step is extremely important-it could lead to correcting a problem without further
checks and can save valuable time. These checks include the following:
| • | Inspect for aftermarket devices which could affect the operation of the
rear compartment release system. Refer to
Checking Aftermarket Accessories
in Wiring Systems. |
| • | Inspect the easily accessible or visible system components and harness
connectors for obvious damage or conditions which could cause the symptom. |
Intermittents
Important:
| • | Check for proper installation of electrical components if an intermittent
condition exists. Inspect for aftermarket theft deterrent devices, lights and cellular
phones. Ensure that no aftermarket equipment is connected to the class 2 circuit.
If you can not locate an intermittent condition, a cellular phone signal may cause
the condition. Faulty electrical connections or wiring may also be the cause of intermittent
conditions. Refer to
Testing for Intermittent Conditions and Poor Connections
in Wiring Systems. |
| • | The problem may or may not turn on the SERVICE VEHICLE SOON indicator
or store a DTC. Do not use the symptom tables to diagnose intermittent conditions.
The malfunction must be present in order to locate the problem. |
| • | Poor electrical connections or wiring cause most intermittent conditions.
Perform a careful visual/physical check for the following conditions: |
| - | Poor mating of the connector halves or a terminal not fully seated in
the connector body (backed out). |
| - | An improperly formed or damaged terminal. |
| - | Reform or replace connector terminals in the problem circuit in order
to insure proper contact tension. |
| - | Poor terminal to wire connection requires removing the terminal from the
connector body in order to perform the check. |
Road test the vehicle with a J 39200
Digital Multimeter (DMM) connected to the suspected circuit. An abnormal
voltage when the malfunction occurs is a good indication that there is a malfunction
in the circuit being monitored.
Use a Scan Tool in order to help detect intermittent conditions. The scan tool
has several features that can be used to locate an intermittent condition. The snapshot
feature can capture and store data parameters within the scan tool when the malfunction
occurs. This information can then be reviewed in order to see what caused the malfunction.
Symptom List
Refer to
Trunk Release Inoperative
in
order to diagnose a symptom that does not set a DTC.
