GM Service Manual Online
For 1990-2009 cars only

Symptom Diagnosis 1999 V Car 4L30-E

Diagnostic Category

Diagnostic Information

Important: The Functional Test Procedure should be performed before beginning any diagnosis. If this procedure has not already been performed, refer to Functional Test .

The following table consists of seven diagnostic categories that are located in the left-hand column of the table. Using this column, choose the appropriate category based on the operating conditions of the vehicle or transmission. After selecting a category, use the right-hand column to locate the specific symptom diagnostic information.

Fluid Diagnosis

This category contains the following topics:

    â€¢ Fluid condition (appearance, contaminants, smell, overheating)
    â€¢ Line pressure (high or low)
    â€¢ Fluid leaks
    â€¢ Refer to Transmission Fluid Check
    â€¢ Refer to Line Pressure Check
    â€¢ Refer to Fluid Leak Diagnosis (procedure)

Noise and Vibration Diagnosis

This category contains the following topics:

    â€¢ Noise (drive gear, final drive, whine, growl, rattle, buzz, popping)
    â€¢ Vibration
    â€¢ Refer to Torque Converter Diagnosis
    â€¢ Refer to Rattling Noises in the Transmission
    â€¢ Refer to Vibration in Second Gear
    â€¢ Refer to Rattling in Torque Converter Clutch

Range Performance Diagnosis

This category contains the following topics:

    â€¢ Engine will not start
    â€¢ Drives in neutral
    â€¢ No park
    â€¢ No reverse
    â€¢ No drive
    â€¢ No engine braking
    â€¢ No or incorrect gear selection
    â€¢ Refer to Engine Will Not Start
    â€¢ Refer to Selector Position P Will Not Engage
    â€¢ Refer to Drives with Selector Lever in Position N
    â€¢ Refer to Rear Wheels Locked
    â€¢ Refer to No Reverse Gear
    â€¢ Refer to No Engine Braking
    â€¢ Refer to No Sport Program
    â€¢ Refer to No Winter Program
    â€¢ Refer to No Kickdown Program

Shift Quality (Feel) Diagnosis

This category contains the following topics:

    â€¢ Harsh engagement (garage shifts)
    â€¢ Delayed engagement (garage shifts)
    â€¢ Shift shudder
    â€¢ Refer to Coarse Shifting from N to D
    â€¢ Refer to Delay in Shifting from N to D
    â€¢ Refer to Slips or Shudders in First Gear

Shift Pattern

This category contains the following topics:

    â€¢ No upshifts
    â€¢ No downshifts
    â€¢ Slipping
    â€¢ Refer to Slips or Shudders in First Gear
    â€¢ Refer to No 1-2 Upshift
    â€¢ Refer to Difficulty in Shifting Between 1-2 Gear
    â€¢ Refer to No 2-3 Upshift
    â€¢ Refer to Difficulty in Shifting Between 2-3 Gear
    â€¢ Refer to No 3-4 Upshift
    â€¢ Refer to Difficulty in Shifting Between 3-4 Gear
    â€¢ Refer to No Downshift Possible

Shift Speed Diagnosis

This category currently has no information.

Currently no information

Torque Converter Diagnosis

This category contains the following topics:

    â€¢ Torque converter diagnosis
    â€¢ TCC does not apply
    â€¢ TCC does not release
    â€¢ Poor acceleration
    â€¢ Refer to Torque Converter Diagnosis
    â€¢ Refer to No Engagement of Torque Converter Clutch
    â€¢ Refer to Cannot Release Torque Converter Clutch
    â€¢ Refer to Rattling in Torque Converter Clutch
    â€¢ Refer to Poor Acceleration