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Test Description

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

  1. 3:  This step tests TCM input response.
  2. 4:  This step tests the wiring harness for opens or shorts.
  3. 6:  This step tests the wiring harness for a short to voltage.
DTC P0708 (Two Connector NSBU)

Step Action Value Yes No
Schematic Reference: Automatic Transmission Controls Schematics
1 Did you perform the Diagnostic System Check - Automatic Transmission? - Go to Step 2  Go to Diagnostic System Check - Automatic Transmission
2 Inspect for proper adjustment of the park/neutral switch. Refer to Park/Neutral Position Switch Adjustment and Shift Cable Adjustment .
Is the park/neutral position switch and shift linkage properly adjusted?		 - Go to Step 3  -
3 
  1. Install the 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 for reference. The Clear Info function will erase the data.
  3. Record the DTC Freeze Frame and Failure Records.
  4. Clear the DTC.
  5. With the scan tool, observe the transmission range (TR) Sw. display while selecting each transmission range, P, R, N, D4, D3, D2, and D1.
Does each selected transmission range match the scan tool TR Sw. display?		 - Go to Diagnostic Aids Go to Step 4 
4 
  1. Turn the ignition OFF.
  2. Disconnect the 4-way connector at the PNP switch.
  3. Turn the ignition ON.
  4. In sequence, connect terminals 4A, 4B, 4C, and 4D in the 4-way PNP connector to terminal 7D in the 7-way PNP connector.
  5. Using the scan tool, monitor transmission range switch status.
Does each selected transmission range match the scan tool TR Sw. display?		 PARK = A and C
REVERSE = A and D
NEUTRAL = C and D
DRIVE 4= B and D
DRIVE 3 = A, B, C, D
DRIVE 2 = A and B
DRIVE 1 = B and C		 Go to Step 8  Go to Step 5 
5 Using the DMM and the J 35616  GM terminal test kit measure the following:
  1. Measure the voltage from terminal A of the TR switch 4-way connector to ground.
  2. Measure the voltage from terminal B of the TR switch 4-way connector to ground.
  3. Measure the voltage from terminal C of the TR switch 4-way connector to ground.
  4. Measure the voltage from terminal D of the TR switch 4-way connector to ground.

Does the voltage measure within the specified value at all four terminals?		 B+ Go to Step 6  Go to Step 7 
6 
  1. Turn the ignition OFF.
  2. Disconnect TCM connector C2 (RED).
  3. Using the DMM and the J 35616  , in sequence, test the signal circuits 5, 6, 7, and 8 of the TCM connector C2 (RED) and A, B, C, and D of the TR switch 4-way connector for a shorted together condition.
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.Did you find and correct the condition?		 - Go to Step 10  Go to Step 9 
7 Test the signal circuits of the TR switch that did not indicate proper voltage for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 10  Go to Step 9 
8
IMPORTANT: A scan tool must be used in order to clear the code from TCM history.
Replace the PNP switch. Refer to Park/Neutral Position Switch Replacement .Did you complete the replacement?		 - Go to Step 10  -
9
IMPORTANT: In most cases, the TCM is not at fault. Investigate thoroughly before replacing the TCM.
Replace the TCM. Refer to Transmission Control Module (TCM) Replacement .Did you complete the replacement?		 - Go to Step 10  -
10 Perform the following procedure in order to verify the repair:
  1. Clear the DTC.
  2. Using the scan tool, monitor the TR Sw. display while selecting each transmission range, P, R, N, D4, D3, D2, and D1.
  3. Select Specific DTC.
  4. Enter DTC P0708.

Has the test run and passed?		 - System OK Go to Step 1 
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