Hello GM has a document on your issue for the code P0894 about the transmission slipping.The torque converter clutch enable solenoid has been found to be cracked down the side of it and has to be replaced along with the wire harness. I'll post the document below.
#06-07-30-007A: Malfunction Indicator Lamp (MIL) On, Diagnostic Trouble Code (DTC) P0894, Harsh 1-2 Shift with 4L60-E, 4L65-E, 4L70-E Auto Transmission (Test/Replace TCC Enable Solenoid/Harness, Auto Trans Wiring) - (Feb 20, 2007)
|Subject:||Malfunction Indicator Lamp (MIL) On, Diagnostic Trouble Code (DTC) P0894, Harsh 1-2 Shift with 4L60-E, 4L65-E, 4L70-E Automatic Transmission (Test and Replace Torque Converter Clutch (TCC) Enable Solenoid / Harness, Auto Trans Wiring)|
|Models:||2006 Cadillac Escalade Models|
|2006 Chevrolet Light Duty Trucks|
|2006 Chevrolet Express Vans|
|2006 GMC Light Duty Trucks|
|with 4L60-E / 4L65-E / 4L70-E (RPOs M30, M32, M70) Automatic Transmission|
This bulletin is being revised to add part number for vehicles with Input Speed Sensor (ISS). Please discard Corporate Bulletin Number 06-07-30-007 (Section 07 -- Transmission/Transaxle
Some customers may comment on a harsh 1-2 shift with the MIL illuminated.
Diagnosis with a scan tool may reveal a DTC P0894.
This condition may be caused by a leaking TCC enable solenoid. The TCC enable solenoid is part of the automatic transmission wiring harness.
Follow the diagnosis and repair procedure below for a DTC P0894.
- With a scan tool, verify the presence of DTC P0894.
- Remove the TCC Enable solenoid / automatic transmission wiring harness. Refer to Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid, TCC Solenoid, and Wiring Harness in the appropriate SI Document.
|• ||Typically if the TCC enable solenoid is found to have a crack / fracture (2), it will be located parallel to the mold seam (1) as shown above.|
|• ||Engineering investigation shows that TCC enable solenoids that are brown in color may exhibit the cracking / fracture condition.|
Air check the TCC enable solenoid using solenoid testing kit.
|• ||Engineering investigation shows that TCC enable solenoids that are off-white in color do not exhibit the cracking / fracture condition.|
Install the TCC enable solenoid into bore #2 of J 44246 as shown above. While air is being applied to the solenoid through J 44246, coat the outside of the solenoid body with transmission fluid to help expose a possible vertical crack in the molded part of the solenoid body. This crack may be very small and not visible without the use of ATF. Complete instructions for the Shift Solenoid Leak Test can be found in SI Document ID # XXXXX
|• ||If NO visual leaks are found in the TCC enable solenoid, refer to DTC P0894 in the appropriate SI Document.|
Replace the TCC enable solenoid. Refer to Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid, TCC Solenoid, and Wiring Harness in the appropriate SI Document. Road test the vehicle.
|• ||If visual leaks are found in the TCC enable solenoid, continue with the next step.|
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