Functional Test

Functional Test

Begin your diagnostics with this Functional Test Procedure, which provides a general outline of how to diagnose an automatic transaxle. This procedure indicates the proper path of diagnosing the transaxle by describing the basic tests and then referencing the locations of the specific tests.

* Inspect the fluid level according to the Fluid Level Service Procedure. Refer to Fluid Leak Diagnosis Fluid Leak Diagnosis.
* Inspect the transaxle for fluid leaks.
* Verify that the transaxle is not burnt by color and smell.
* Ensure that the transaxle is not in limp home mode (LHM).
* Inspect the battery terminals and the ground connections for corrosion or looseness.
* Verify that the cooler flow is not restricted.
* Test all electrical connections for tightness.
* Use an on-board diagnostic tool or a scan tool to see if any transaxle trouble codes have been set. Refer to Diagnostic Trouble Code (DTC) List/Type ZF 4HP 16 - Automatic Transmission and repair the vehicle as directed. Perform the road test and verify that the code has not set again. Refer to Road Test ZF 4HP 16 - Automatic Transmission.
* Perform the electrical/garage shift tests. Refer to Harsh Garage Shift Harsh Garage Shift.
* Perform the road test. Refer to Road Test ZF 4HP 16 - Automatic Transmission.
* Inspect the oil and look for metal or other contaminates in the oil pan.