LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2006 >> Sierra 1500 HD, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 29 (Automatic Transmission - 4L60-E/4L65-E/4L70-E - DTC P0218 To DTC P0785) >> DTC P0742 >> Test Description

Test Description

WARNING: This page is about a different variant/trim than selected.

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

  1. 2:  This step tests the hydraulic state of the TCC. When the PCM commands the TCC solenoid valve OFF, the slip speed should increase.
DTC P0742

Step Action Values Yes No
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. IMPORTANT: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the PCM.
  4. Record the DTC Freeze Frame and Failure Records.
  5. Clear the DTC.
  6. Drive the vehicle in the D4 drive range in second, third or fourth gear under steady acceleration, with a TP angle at 20%.
While the scan tool TCC Enable status is NO, does the scan tool display a TCC Slip Speed within the specified range?
-20 to +20 RPM Go to Step 3  Go to Diagnostic Aids 
3 The TCC is hydraulically stuck ON. Inspect for the following:
  • Clogged exhaust orifice in the TCC solenoid valve.
  • Converter clutch apply valve stuck in the apply position.
  • Misaligned or damaged valve body gasket.
  • Restricted release passage.
  • Restricted transmission cooler line.

Did you find and correct the condition?
- Go to Step 4  -
4 Perform the following procedure in order to verify the repair:
  1. Select DTC.
  2. Select Clear Info.
  3. Drive the vehicle in D4 with the TCC OFF and the throttle above 17%. Ensure that the scan tool TCC Slip Speed is 100-2,000 RPM for 5 seconds.
  4. Select Specific DTC.
  5. Enter DTC P0742.

Has the test run and passed?
- Go to Step 5  Go to Step 2 
5 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