P2704-INADEQUATE ELEMENT VOLUME 4C

For a complete wiring diagram Refer to Section 8W.

Theory of Operation


The volumes of the 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 volumes resulting in setting a DTC. The DTC will usually set with other DTCs, which indicates an internal transmission problem.



Possible Causes
BROKEN 4C RETURN SPRING OR DISLODGED SNAP RING
BROKEN 4C ACCUMULATOR SPRING(S)
HYDRAULIC LEAK IN THE VALVE BODY
TRANSMISSION SOLENOID/TRS ASSEMBLY
POWERTRAIN CONTROL MODULE

Always perform the 45RFE/545RFE Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE - STANDARD PROCEDURE)



Diagnostic Test

1. CHECK THE 4C CLUTCH VOLUME

With the scan tool, record the 4C clutch volume index (CVI) and erase DTCs.
Perform at least 10, 3-4 upshifts with the throttle between 10 and 54 degrees. The Transmission temperature must be at least 43 degrees C or 110 degrees F.
With the scan tool, read the 4C CVI.

Is the current 4C CVI below 10?

Yes


No

2. DTC P0876 PRESENT

With the scan tool, check DTCs.

NOTE: The DTC P0876 must also be set with P2704 in order for this test to be valid.



Is the DTC P0876 also present?

Yes


No

3. 4C CLUTCH CIRCUIT LEAKS IN THE VALVE BODY

Turn the ignition off to the lock position.
Remove the transmission oil pan per the Service Information.
Remove the valve body per the Service Information.
Check condition of the 4C accumulator springs.
Look for possible leak paths into the 4C clutch hydraulics circuit within the valve body.

Were any problems found?

Yes


No

4. AIR CHECK 4C CLUTCH CIRCUIT

Perform an air check on the 4C Clutch circuit per the Service Information.
Listen for proper 4C Clutch piston movement.

Were any problems found?

Yes


No

5. VERIFY PCM OPERATION

Perform eight learnable starts. A learnable start is defined as follows: Start engine. From a standstill, accelerate lightly to 50 MPH, then brake lightly to a stop. Turn off engine.
With the scan tool, record Transmission CL VOL INDEX (CVI) for all clutches.
With the scan tool, perform a BATTERY DISCONNECT.
With the scan tool, read the CVIs and compare them to the reading recorded before the BATTERY DISCONNECT.

Are any of the CVIs less than 5 or are they different than before the battery disconnect?

Yes


No