Powertrain Control Module (PCM) - 66RFE
P2703- INADEQUATE ELEMENT VOLUME UD
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The volume of transmission fluid needed to apply the friction elements are continuously monitored and learned for adaptive controls. As the clutch friction material wears, the volume of fluid needed to apply the clutch increases. Certain transmission mechanical problems can cause near-zero learned volume resulting in setting a DTC. The DTC will usually set with other DTCs which indicates an internal transmission problem.
- When Monitored:
When the engine is running. The UD Clutch Volume Index (CVI) is updated during a 5-4 kickdown with throttle angle between 10 and 54 degrees. Transmission temperature must be at least 43° C (110° F).
- Set Condition:
When the UD CVI falls below 11.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. OTHER DTCs PRESENT
1. With the scan tool, check for transmission DTCs.
Are any Pressure Switch Sense circuit DTCs present?
Yes
- Testing and Inspection Perform the appropriate diagnostic procedure.
No
- Go To 2
2. CHECK UD CLUTCH VOLUME INDEX
1. With the scan tool, erase transmission DTCs.
NOTE: The TRANS TEMP DEG must be at least 43° C or 110° F before performing the following steps.
2. Drive the vehicle and perform ten 5-4 kickdowns by applying the throttle between 40 and 50 TPS degrees at speeds about 1500 to 1700 rpm on the Output Speed sensor.
3. With the scan tool, read the UD CVI.
Is the UD CVI below 10?
Yes
- Go To 3
No
- Go To 5
3. UD CLUTCH CIRCUIT LEAKS IN THE VALVE BODY
1. Turn the ignition off to the lock position.
2. Remove the transmission oil pan and valve body.
3. Check the condition of the UD accumulator springs.
4. Look for possible leak paths into the UD clutch hydraulics circuit within the valve body.
Were any problems found?
Yes
- Repair as necessary.
- Perform the 66RFE TRANSMISSION VERIFICATION TEST. 66RFE Transmission Verification Test.
No
- Go To 4
4. AIR CHECK UD CLUTCH CIRCUIT
1. Perform an air check on the UD Clutch circuit.
2. Watch and listen for UD Clutch piston movement.
3. Air check all other pump passages for air leakage into the UD Clutch circuit.
Were any problems found?
Yes
- Repair internal transmission. Pay attention to components related to the UD clutch. Broken or weak return spring or a dislocated snap ring. If no trouble is found in UD clutch component or UD clutch leakage was noted in passage, replace the Pump Assembly.
- Perform the 66RFE TRANSMISSION VERIFICATION TEST. 66RFE Transmission Verification Test
No
- Replace the Transmission/TRS Solenoid Assembly. With the scan tool, perform a Quick Learn.
- Perform the 66RFE TRANSMISSION VERIFICATION TEST. 66RFE Transmission Verification Test
5. VERIFY PCM OPERATION
NOTE: The TRANS TEMP DEG must be at least 43° C or 110° F before performing the following steps.
1. Perform eight learnable starts. A learnable start is defined as follows: Start the engine and accelerate lightly to 80 Km/h or 50 mph then brake lightly to a stop. Turn the engine off.
2. With the scan tool, record the clutch volume index CVI for all clutches.
3. With the scan tool, perform a BATTERY DISCONNECT.
4. With the scan tool, read the CVIs and compare them to the readings recorded before the BATTERY DISCONNECT.
Are any of the CVIs less than 5 or different than before the BATTERY DISCONNECT?
Yes
- Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the PCM. With the scan tool, perform a Quick Learn.
- Perform the 66RFE TRANSMISSION VERIFICATION TEST. 66RFE Transmission Verification Test
No
- Test Complete.