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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1867 (Automatic Transaxle - 4T45-E - DTC P0719 To DTC P0842) >> DTC P0787 (2.4L Hybrid) >> Test Description

Test Description

WARNING: This page is about a different car, the 2007 Saturn Vue. 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. 8:  This step tests the electrical operation of the solenoid.
  2. 9:  This step tests the TCM and the wiring to the transmission.
  3. 14:  This step verifies that the circuit has the correct resistance.
DTC P0787

Step Action Value(s) 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 TCM.
  3. Record the DTC Freeze Frame and Failure Records.
  4. Clear the DTC.
Is DTC P0973, P0976, or P2764 also set?		 - Go to Step 3  Go to Step 8 
3
  1. Remove the TRANS fuse.
  2. Inspect the fuse for an open. Refer to Circuit Protection - Fuses .
Did you find the condition?		 - Go to Step 4  Go to Step 6 
4
IMPORTANT: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics for complete circuit distribution.
Test the ignition 1 voltage circuit of the 4-3 downshift solenoid valve for a short to ground between the underhood fuse block and the AT inline 20-way connector. Refer to Testing for Short to Ground andWiring Repairs .Did you find and correct the condition?		 - Go to Step 23  Go to Step 5 
5
IMPORTANT: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics for complete circuit distribution.
Test the ignition 1 voltage circuit of the 4-3 downshift solenoid valve for a short to ground between the AT inline 20-way connector and the 4-3 downshift solenoid valve.Refer to Testing for Short to Ground .Did you find the condition?		 - Go to Step 20  -
6 Test the ignition 1 voltage circuit of the 4-3 downshift solenoid valve for an open between the underhood fuse block and the AT inline 20-way connector. Refer to Testing for Continuity and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 23  Go to Step 7 
7 Test the ignition 1 voltage circuit of the 4-3 downshift solenoid valve for an open between the AT inline 20-way connector and the 4-3 downshift solenoid valve. Refer to Testing for Continuity .
Did you find the condition?		 - Go to Step 20  -
8 
  1. Use the scan tool in order to command the 4-3 downshift solenoid valve ON and OFF 3 times.
  2. Listen at the transmission bottom pan.
Does the solenoid click when commanded ON and OFF?		 - Go to Testing for Intermittent Conditions and Poor Connections Go to Step 9 
9 
  1. Turn OFF the ignition.
  2. Disconnect the AT inline 20-way connector. Additional DTCs may set.
  3. Install the J 44152  Jumper Harness (20 pins) on the engine side of the AT inline 20-way connector. See Special Tools .
  4. Using the J 35616  GM-approved terminal test kit, connect a test lamp between the ignition 1 voltage and the 4-3 downshift solenoid valve control circuits of the J 44152  . See Special Tools . Refer to Automatic Transmission Inline 20-Way Connector End View .
  5. Turn ON the ignition, with the engine OFF.
  6. Command the 4-3 downshift solenoid valve ON and OFF three times.
Is the test lamp ON when you command the solenoid ON, and OFF when you command the solenoid OFF?		 - Go to Step 14  Go to Step 10 
10 Is the test lamp always ON? - Go to Step 11  Go to Step 13 
11
  1. Turn OFF the ignition.
  2. Disconnect the TCM connector. Additional DTCs may set.
  3. Turn ON the ignition, with the engine OFF.
Is the test lamp ON?		 - Go to Step 12  Go to Step 22 
12 Test the control circuit of the 4-3 downshift solenoid valve for a short to ground between the TCM connector and the AT inline 20-way connector. Refer to Testing for Continuity and Wiring Repairs .
Refer to Testing for Short to Ground and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 23  -
13 Test the control circuit of the 4-3 downshift solenoid valve for an open between the TCM connector and the AT inline 20-way connector.
Did you find and correct the condition?		 - Go to Step 23  Go to Step 22 
14 
  1. Turn OFF the ignition.
  2. Disconnect the J 44152  from the engine side of the AT inline 20-way connector. See Special Tools .
  3. Install the J 44152  on the transmission side of the AT inline 20-way connector. See Special Tools .
  4. Using the DMM and the J 35616  GM-approved terminal test kit, measure the resistance between the ignition 1 voltage and the 4-3 downshift solenoid valve control circuits of the J 44152  . See Special Tools .
Refer to Automatic Transmission Inline 20-Way Connector End View .Is the resistance within the specified range?		 19-31 Ω Go to Step 17  Go to Step 15 
15 Is the resistance greater than the specified value? 31 Ω Go to Step 16  Go to Step 17 
16
  1. Test the control circuit of the 4-3 downshift solenoid valve for an open between the AT inline 20-way connector and the 4-3 downshift solenoid valve.
  2. Test the ignition 1 voltage circuit of the 4-3 downshift solenoid valve for an open between the AT inline 20-way connector and the 4-3 downshift solenoid valve.
Refer to Testing for Continuity .Did you find a condition?		 - Go to Step 20  Go to Step 21 
17 Measure the resistance from the 4-3 downshift solenoid valve control circuit of the J 44152  to ground. See Special Tools . Refer to Automatic Transmission Inline 20-Way Connector End View .
Is the resistance less than the specified value?		 100 Ω Go to Step 18  Go to Step 19 
18 Test the control circuit of the 4-3 downshift solenoid valve for a short to ground between the AT inline 20-way connector and the 4-3 downshift solenoid valve. Refer to Testing for Short to Ground .
Did you find the condition?		 - Go to Step 20  -
19 Measure the resistance between the 4-3 downshift solenoid valve control circuit and all other terminals of the J 44152  . See Special Tools .
Refer to Automatic Transmission Inline 20-Way Connector End View .
Is the resistance less than the specified value?		 100 Ω Go to Step 20  Go to Step 21 
20 Replace the automatic transmission wiring harness. Refer to Wiring Harness Replacement .
Did you complete the replacement?		 - Go to Step 23  -
21 Replace the 4-3 downshift solenoid valve. Refer to Control Valve Body Spacer Plate and 4-3 Downshift On/Off Solenoid Removal and Control Valve Body Spacer Plate and 4-3 Downshift On/Off Solenoid Installation .
Did you complete the replacement?		 - Go to Step 23  -
22 Replace the TCM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 23  -
23 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:
    • Drive the vehicle in D4.
    • Allow the transmission to shift through all gears.
  4. Select Specific DTC.
  5. Enter DTC P0787.

Has the test run and passed?		 - Go to Step 24  Go to Step 2 
24 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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