| Subject: | DTC P0756, P0796, P2714, P2723, TCC Shudder or Harsh Engagement, Harsh Shifts, Water in Transmission - keywords code converter fluid torque |
| Models: | 2008 Cadillac CTS, Escalade, Escalade ESV, Escalade EXT, SRX, STS, STS-V, XLR, XLR-V |
| 2008 Chevrolet Corvette, Silverado |
| 2008 GMC Sierra, Yukon Denali, Yukon Denali, XL |
| Equipped With 6L50, 6L80 or 6L90 (RPOs MYB, MYC, MYD) Automatic Transmission |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some customers may comment on a transmission concern where the MIL is illuminated and DTC P0756, P0796, P2714 or P2723 may be found in the TCM as active or history codes. They may also comment on TCC shudder during engagement, harsh TCC apply or harsh
upshifts. Investigation of these concerns may find that the transmission fluid is contaminated with water. Contaminated fluid may have a milky appearance and be pink in color looking like a strawberry milkshake.
Recommendation/Instructions:
If the transmission fluid is found to be contaminated, stop all repairs and contact TAC at the number you have been provided. An engineering investigation is being conducted to determine the source of the water. Please obtain a sample of the transmission
fluid from the oil pan in a clean, dry bottle. If the pan is already drained a sample may be extracted from the torque converter. The sample should be approximately 8 oz (250 ml) minimum. These samples will be shipped for analysis purposes. Please contact
TAC for shipping instructions. The transmission vent system and dip stick tube (if equipped) should also be checked for signs of possible water entry.
Initial reports indicate that this contamination is due to water, not coolant caused by a leaking transmission oil cooler.
Important: For vehicles suspected of having a leaking transmission oil cooler that would cause contamination of the transmission fluid with coolant, the following check should be performed before deciding to replace the radiator.
| • | Remove the surge tank cap and examine the coolant for signs of contamination with transmission fluid (if contaminated, the coolant will have a milky, not clear appearance). |
| • | If the coolant has a normal, clear appearance, the radiator should not be replaced. |
| • | The cooler can also be tested by following SI procedure Cooling System Leak Testing. Do NOT replace a radiator without verifying that the transmission oil cooler is leaking. |
| | If water or coolant is found in the transmission, it must
be repaired by following SI procedure Engine Coolant / Water in Transmission document number #49588. |
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
