Pretrip Test

Pretrip Test Conditions

The current unit settings are saved and restored at the end of the Pretrip Test or if the unit is turned off and back on.
The Pretrip Test can be run in either Diesel or Electric Mode.
The unit will auto switch from Diesel Mode to Electric Mode or from Electric Mode to Diesel Mode during a Pretrip Test if these features are enabled and the auto switch conditions occur.

Pretrip tests proceed in the order shown below.

Full Pretrip Tests include all of the tests shown below.

Amp Checks - Each electrical control component is energized and the current drawn is confirmed as within specification.
Engine Start - The Engine will start automatically.
Defrost - If the coil temperature is below 45°F (7°C), a defrost cycle is initiated.
RPM Check - The engine RPM in high and low speed is checked during the Cool Check.
Cool Check - The ability of the unit to cool in low speed is checked.
Heat Check - The ability of the unit to heat in low speed is checked.
Report Test Results - The test results are reported when the Pretrip Test is completed. If the Pretrip Test fails, alarm codes will exist to direct the technician to the source of the problem.

Engine Running Pretrip Tests include all of the tests shown below. They do not include the Amps Check or the Engine Start tests.

Defrost - If the coil temperature is below 45°F (7°C), a defrost cycle is initiated.
RPM Check - The engine RPM in high and low speed is checked during the Cool Check.
Cool Check - The ability of the unit to cool in low speed is checked.
Heat Check - The ability of the unit to heat in low speed is checked.
Report Test Results - The test results are reported when the Pretrip Test is completed. If the Pretrip Test fails, alarm codes will exist to direct the technician to the source of the problem.

When performing a Pretrip Test, the following issues should be considered.

Whenever possible, run the Pretrip Test with an empty truck box.
If running a Pretrip Test on a truck loaded with dry cargo, verify that proper airflow can occur around the load. If the load restricts airflow, false test results may occur. Units have high refrigeration capacity which results in rapid temperature change. Sensitive dry cargo may be damaged as a result.
If running a Pretrip Test on a truck that has just been washed down, the extremely high humidity inside the truck box may result in false test results.
If running a Pretrip Test on a truck loaded with sensitive cargo, monitor the load temperature during the test as normal temperature control is suspended during pre-trip operation.
Always perform Pretrip Tests with the cargo doors closed to prevent false test results.