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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 143 (Automatic Transmission - 4L80-E/4L85-E - DTC P0218 To DTC P0976) >> DTC P0894 >> Test Description

Test Description

WARNING: This page is about a different car, the 2007 GMC Yukon XL and 2007 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

  1. 3:  This step tests the indicated range signal to the actual selected range. A faulty TFP manual valve position switch can set a DTC P0894.
  2. 4:  This step tests for excessive TCC slip speed while in a commanded TCC lock-up state and in fourth gear; and confirms that the fault is present.
  3. 5:  This step tests for excessive TCC slip speed while in a commanded TCC lock-up state and in third gear.
  4. 6:  This step tests for a sticking TCC shift valve.
  5. 7:  This step tests for proper transmission line pressure.
DTC P0894

Step Action Value Yes No
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2 Perform the Transmission Fluid Checking Procedure. Refer to Transmission Fluid Checking .
Did you perform the Transmission Fluid Checking Procedure?		 - Go to Step 3  Go to Transmission Fluid Checking
3 
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
    3. IMPORTANT: Before clearing the DTCs, use the scan tool in order to record the ECM and TCM Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and TCM.
  3. Record the Freeze Frame and Failure Records.
  4. Clear the DTCs.
  5. With the engine idling and at normal operating temperature, apply the brake pedal.
  6. Select each transmission range: D1, D2, D3, D4, N, R, and P. Refer to Transmission Fluid Pressure Manual Valve Position Switch Logic .
Does each selected transmission range match the scan tool TFP switch A/B/C display?		 - Go to Step 4  Go to DTC P1810
4  Drive the vehicle under the following conditions:
  • The TFT is between 20-130°C (50-266°F).
  • The transmission is in D4.
  • The TCC duty cycle is 65% or greater.
  • The calc. throttle position is 8% or greater.

At any time is the TCC slip speed greater than the specified value for 10 seconds?		 120 RPM Go to Step 5  Go to Diagnostic Aids
5  Drive the vehicle under the following conditions:
  • The transmission is in D3.
  • Command the TCC ON with the scan tool.
  • The TP angle is 8% or greater.

At any time is the TCC slip speed greater than the specified value for 10 seconds?		 120 RPM Go to Step 7  Go to Step 6 
6  Repeat the procedure in Step 4. Drive the vehicle under the following conditions:
  • The transmission is in D4.
  • The TCC duty cycle is 65% or greater.
  • The calc. throttle position is 8% or greater.

Is the TCC slip speed greater than the specified value?		 120 RPM Go to Step 8  Go to Diagnostic Aids
7 
  1. Connect the J 21867  pressure gage to the transmission line pressure tap.
  2. Perform the Line Pressure Check Procedure. Refer to Line Pressure Check .
Were the line pressures within specifications during the Line Pressure Check Procedure?		 - Go to Step 8  Go to Symptoms - Automatic Transmission
8
  1. Inspect the transmission for the following conditions:
  2. Repair the condition as necessary.
Did you complete the repair?		 - Go to Step 10  Go to Step 9 
9
  1. Inspect the transmission for the following conditions:
  2. Repair the condition as necessary.
Did you complete the repair?		 - Go to Step 10  -
10 Perform the following procedure in order to verify the repair:
  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
    • Ensure that TFT is between 20-130°C (50-266°F).
    • Drive the vehicle in 4th gear, with the TCC commanded ON.
    • The calc. throttle position is 8% or greater.
    • The TCM must see a TCC Slip Speed of -20 to +40 RPM for 6 seconds or greater.
  4. Select Specific DTC.
  5. Enter DTC P0894.

Has the test run and passed?		 - Go to Step 11  Go to Step 2 
11 With the scan tool, observe the stored information, capture info and DTC info.
Does the scan tool display any DTCs that you have not diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
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