A/T - Harsh 1-2 Shift/MIL ON/DTC P0894 Set
TSB SB08-04-S001Issue Date: FEBRUARY 2008
Malfunction Indicator Lamp (MIL) On, Diagnostic Trouble Code (DTC) P0894, Harsh 1-2 Shift With 4L60-E Auto Transmission
(This Bulletin Supersedes SB07-04-S001)
Affected Vehicles
2006 Isuzu Ascender
2006 Isuzu i-280/i-350 (TI)
Service Information
This bulletin is being revised to update Warranty Information.
Condition:
Some customers may comment on a harsh 1-2 shift with the MIL illuminated. Diagnosis with a scan tool may reveal a DTC P0894.
Possible Cause:
This condition may be caused by a leaking TCC enable solenoid. The TCC enable solenoid is part of the automatic transmission wiring harness.
Correction:
Test and if necessary replace TCC enable solenoid/harness, auto transmission wiring.
Service Procedure
Follow the diagnosis and repair procedure below for a DTC P0894.
1. With a scan tool, verify the presence of DTC P0894.
2. 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 Service Manual.
^ 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.
Tip
^ Engineering investigation shows that TCC enable solenoids that are brown in color may exhibit the cracking / fracture condition.
^ Engineering investigation shows that TCC enable solenoids that are off-white in color do not exhibit the cracking / fracture condition.
3. Air check the TCC enable solenoid using the Kent Moore J 44246 Solenoid Testing Kit available though Kent Moore at (800) 345-2233.
4. Install the TCC enable solenoid into bore # 2 of the Kent Moore J 44246 as shown.
5. While air is being applied to the solenoid through the Kent Moore 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 the Service Manual.
^ If NO visual leaks are found in the TCC enable solenoid, refer to DTC P0894 in the Service Manual.
^ If visual leaks are found in the TCC enable solenoid, continue with the next step.
6. Replace the TCC enable solenoid. Refer to Torque Converter Clutch Pulse Width Modulation (TCC PWM) Solenoid, TCC Solenoid, and Wiring Harness in the Service Manual.
7. Road test the vehicle.
Parts Information
Warranty Claim Information
Always refer to the Isuzu Service Policy Procedure Manual for specific details on warranty coverage and policies. Reference published Labor Time Guide for claim processing, if applicable.
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