Preliminary Inspection
The following items must be checked prior to beginning the diagnostic procedures:

Know and Understand the Concern
In order to correctly diagnose a concern, first understand the customer complaint or condition. Customer contact may be required in order to begin to verify the concern. Understand the conditions as to when the concern occurs. For example:

• Hot or cold vehicle temperature.
• Hot or cold ambient temperature.
• Vehicle driving conditions.
• Vehicle loaded/unloaded.

After understanding when and how the concern occurs, proceed to Verification of Condition.

Verification of Condition

NOTE: Some transmission conditions may cause engine concerns. If the torque converter clutch does not disengage, the engine will stall.

This provides information which must be used in both determining the actual cause of customer concerns and carrying out the appropriate procedures.

Determine Customer Concern
Determine customer concerns relative to vehicle use and dependent driving conditions, paying attention to the following items:

• hot or cold vehicle operating temperatures
• hot or cold ambient temperatures
• type of terrain
• vehicle loaded/unloaded
• city/highway driving
• upshift
• downshift
• coasting
• engagement
• noise/vibration