The Functional Test Procedure is the first step in diagnosing mechanical or hydraulic transmission conditions. The Functional Test provides procedures and references to the Symptom Diagnosis table for specific diagnostic information.

Important: Engine performance can strongly affect transmission performance. Make sure that the complaint is not the result of poor engine performance before continuing.

Verify the customer complaint.

Has the customer complaint been verified?

Go to Step 2 .

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Important: Many transmissions have default actions that take place once a DTC fault is detected. These actions may appear to be transmission concerns.

Has the Diagnostic System Check - Automatic Transmission been performed?

Go to Step 3 .

Go to Diagnostic System Check - Automatic Transmission .

Perform a visual inspection. Look for the following conditions:

Was an item identified that needs service?

Go to the Appropriate Repair or Diagnosis Section.

Go to Step 4 .

Perform the Transmission Fluid Check .

Is the procedure complete?

Go to Step 5 .

Go to Transmission Fluid Check .

Perform the Road Test .

Did the vehicle exhibit any objectionable performance condition?

Go to Step 6 .

Go to Step 1 .

Did the vehicle exhibit objectionable torque converter operation?

Go to Step 15 .

Go to Step 7 .

Did the vehicle produce any objectionable noise condition?

Go to Symptoms - Automatic Transmission .

Go to Step 8 .

Did the vehicle exhibit a vibration condition?

Go to Step 9 .

Go to Step 10 .

Did the vibration occur only during TCC apply or release?

Go to Step 15 .

Go to Symptoms - Automatic Transmission .

Did the vehicle exhibit a shift speed condition such as low or high shift speeds?

Go to Symptoms - Automatic Transmission .

Go to Step 11 .

Check for unacceptable shift quality.

Did the vehicle exhibit any of these shift quality conditions?

Go to Step 12 .

Go to Step 13 .

Perform the Line Pressure Check .

Is the line pressure within specification?

Go to Symptoms - Automatic Transmission .

Go to Symptoms - Automatic Transmission .

Check for unacceptable shift pattern conditions?

Did the vehicle exhibit any of these shift pattern conditions?

Go to Symptoms - Automatic Transmission .

Go to Step 14 .

Check for unacceptable range performance conditions?

Did the vehicle exhibit any of these range performance conditions?

Go to Symptoms - Automatic Transmission .

System OK.

Check for these specific torque converter or TCC malfunctions?

Did the vehicle exhibit any of these torque converter or TCC conditions?

Go to Torque Converter Diagnosis .

System OK.