Parking the vehicle,
performing tests or making adjustments,
leaving the vehicle standing with the engine running.
Know and understand customer concern
The problem must be fully understood before fault diagnosis is started, in order to clearly
establish the cause of a concern. Detailed information from the customer may be needed
for this.
Ask the customer under which conditions the concern appears. For example:
Cold or warm engine?
At what engine speed, vehicle speed, load?
In which gear or range?
At high or low outdoor temperature?
With the vehicle loaded or empty?
On what road surface?
In what driving situation:
while accelerating?
on overrun?
when shifting up or down?
Do noises occur?
What is the quality of the shift?
Does the gear engaged correspond to the display?
When the incorrect operation occurred, did a warning appear in the IC?
Verification of Condition
NOTE: If noise or vibration is a concern, check for dependency on: rpm, vehicle speed,
gear range or temperature.
NOTE: In some cases, faults in the automatic transmission may cause concerns over the
way the engine runs. For example, it can cause the engine to stall if the torque converter
lock-up clutch does not disengage.
If necessary and it is possible, ask the customer to demonstrate the concern to you. It may
also be an error in the way in which the vehicle is operated. Reproduce the fault by possibly
driving the vehicle yourself.
Visual Inspection
The visual inspection extends to obvious damage to mechanical or electrical
components, e. g.
Electrical connectors and cable connections
Ease of operation of the selector lever
Selector lever position and selector lever display
Fluid leakage
Transmission fluid level check
Transmission fluid quality check
Modifications/retrofitting/tuning
Damage
If any causes for a concern are found during the visual inspection, they must be corrected
before any further checks are made.
Electrical connectors and cable connections
Electrical connectors to and from the automatic transmission control electronics must only
be separated or connected when no voltage is present.
Ease of operation of the selector lever
A selector lever which is difficult to move may be the cause of a customer concern.
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