The function test procedure is designed to verify the correct operation of components in the transmission and to identify whether a condition is electrical in nature, or not. This will eliminate the unnecessary removal of transmission components and time loss in rectification. The test is the first step in diagnosing mechanical or hydraulic transmission conditions and provides procedures and references to the Symptom Diagnostic table for specific diagnostic information.
Step | Action | Yes | No | ||||||||||||||||||
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1 | Verify the customer complaint. Has the customer complaint been verified? | Go to Step 2 | -- | ||||||||||||||||||
2 | Has the Powertrain On Board Diagnostic (OBD) System Check been performed? | Go to Step 3 | |||||||||||||||||||
3 |
Was an item identified that needs service? | Go to the Appropriate Repair or Diagnosis Section | Go to Step 4 | ||||||||||||||||||
4 | Perform the Transmission Fluid Checking Procedure in 7D4 Automatic Transmission - 4L65E - On-vehicle Service. Is procedure complete? | Go to Step 5 | Refer to Transmission Fluid Check | ||||||||||||||||||
5 | Perform the road test procedure, refer to Road Test Is the procedure complete? | Go to Step 6 | System OK | ||||||||||||||||||
6 | Did the vehicle exhibit objectionable torque converter operation? | Go to Step 15 | Go to Step 7 | ||||||||||||||||||
7 | Did the vehicle exhibit a noise condition? | Refer to Noise and Vibration Analysis | Go to Step 8 | ||||||||||||||||||
8 | Did the vehicle exhibit vibration condition? | Go to Step 9 | Go to Step 10 | ||||||||||||||||||
9 | Did the vibration occur only during TCC apply or release? | Go to Step 15 | Refer to Noise and Vibration Analysis | ||||||||||||||||||
10 | Did the vehicle exhibit a shift speed condition such as low or high shift speeds? | Go to Inaccurate Shift Points | Go to Step 11 | ||||||||||||||||||
11 | Check for any if the following shift quality (feel) conditions:
Were any of these conditions evident? | Go to Step 12 | Go to Step 13 | ||||||||||||||||||
12 | Perform the line pressure check procedure, refer to Line Pressure Check Is the line pressure within specification? | Refer to Line Pressure | Refer to Functional Test | ||||||||||||||||||
13 | Road test to check for any of the following shift pattern conditions:
Were any of these conditions evident? | Refer to Shift Speed | Go to Step 14 | ||||||||||||||||||
14 | Check for any of the following range performance conditions:
Were any of these conditions evident? | System Serviceable | |||||||||||||||||||
15 | Refer to Torque Converter Diagnosis to check whether the vehicle exhibits any of the following TCC conditions:
Were any of the above TCC conditions evident? | System Serviceable |