System Operational Test

Fig. 26 Rear Leveling Diagnostic Test Pin Location:

A test weight of 275-300 lbs. must be added before starting diagnosis tests.

PREPARATION

The following system test operation is started only by connecting the diagnostic ground terminal to ground after the ignition switch is turned to the On position. A monitor lamp must be connected between the Test lamp ground terminal to display the control module status.
1. Remove protective connector cover from diagnosis connector located behind the right rear quarter trim panel.
2. Insert a wire into diagnostic ground terminal, then attach to compressor ground terminal or as an alternate, insert wire into diagnostic ground terminal. Ground other end of test wire to body ground or a control module fastener.

OPERATION

1. The compressor relay output, from the Control Module (CM), is activated until the vehicle is in the high position. The maximum relay output operation time is 140-160 seconds. If the expected position is not obtained, the CM ceases test and any further operation. The monitor lamp output is continuously activated until the ignition is cycled from Off to On or 1 hour has passed after the ignition switch was turned to the Off position.
2. The monitor lamp output should flash to indicate the position of the height sensor. The sensor should be in the high position. A continuously lighted monitor lamp will indicate a failure.
3. Next the exhaust solenoid output is activated until the vehicle is in the low position. The maximum exhaust solenoid operation time is 110-130 seconds. If the expected position is not obtained, the CM ceases test and any further operation. The monitor lamp output is lighted continuously until the ignition is cycled from Off to On or 1 hour has passed after the ignition switch was turned to the Off position.
4. The monitor lamp should flash to indicate the height sensor in the low position. A continuously lighted monitor lamp will indicate a failure.
5. The compressor relay output is activated to return the vehicle to the level position. The maximum operation time of the relay is 140-160 seconds. If the expected position is not obtained, the CM ceases test and any further operation. The monitor lamp is continuously lighted until the ignition is cycled from Off to On or 1 hour has passed after the ignition switch was turned to the Off position.
6. Completion of test is when test successfully completed, the CM resumes normal operation. The test is now complete. throughout the testing, the vehicle load must be maintained, no loads are allow to be added or removed to or from the vehicle once the test have been started.
7. If any of the tests fail, refer to DIAGNOSIS.

VERIFICATION TEST

To verify system operation test, disconnect test ground wire then reconnect and perform test again.
Termination Of Test
The test operation is terminated when any of the following takes place:
1. Disconnecting the diagnostic input from ground circuit. Turning ignition switch to Off position.
When test operation is terminated, the CM resumes normal operation unless it ceases operation due to it detecting a system malfunction.