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Test Description

WARNING: This page is about a different car, the 2004 Pontiac Vibe. 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. 1:  The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
  2. 3:  This step checks for proper shift points.
  3. 5:  This step checks for a leaky shift solenoid #1.
  4. 6:  This step checks for a stuck closed shift solenoid #1.
  5. 8:  This step checks the condition of the valve body assembly.
  6. 9:  This step checks for a faulty PCM.
DTC P0751

Step Action Yes No
Schematic Reference: Automatic Transmission Controls Schematics 
1  Was the On-Board Diagnostic (OBD) System Check performed? Go to Step 2  Go to Diagnostic System Check - Engine Controls in Engine Controls
2
  1. Install a scan tool.
  2. Turn the ignition to ON, leaving the engine OFF.
  3. Perform the scan tool Clear DTC Information function.
  4. Operate the vehicle within the Freeze Frame conditions as observed.
Does the scan tool display any other DTCs in addition to DTC P0751?		 Go to applicable DTC table Go to Step 3 
3  Perform the Upshifts and Torque Converter Clutch Apply Procedure in Road Test Procedure  in order to diagnose mechanical condition of transaxle.
Is the action complete?		 Go to Step 4  -
4 Perform the DTC Confirmation Procedure.
Did this DTC reset?		 Go to Step 5  Go to Step 11 
5 
  1. Remove shift solenoid #1.
  2. Apply 490 kPa (71 psi) of compressed air into shift solenoid #1 inlet port.
Did shift solenoid #1 outlet port open and air escape?		 Go to Step 6  Go to Step 12 
6 
  1. Apply 12V to shift solenoid #1 - positive to wire, negative to case.
  2. Apply 490 kPa (71 psi) of compressed air into shift solenoid inlet.
Did shift solenoid #1 outlet port open and air escape?		 Go to Step 7  Go to Step 12 
7 Refer to DTC P1780  for diagnosis of PNP switch.
Is the action complete?		 Go to Step 8  -
8  Remove valve body and inspect the passages for any obstructions/restrictions. Refer to Solenoids and Wiring Harness Replacement .
Is the valve body in good condition?		 Go to Step 9  Go to Step 10 
9 
  1. Install a good PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls.
  2. Perform the DTC Confirmation Procedure.
Does this DTC reset?		 Go to Step 13  Go to Step 14 
10 Repair or overhaul the valve body assembly. Refer to Solenoids and Wiring Harness Replacement .
Is the action complete?		 Go to Step 15  Go to Step 14 
11 A malfunction is not present at this time. Refer to Diagnostic Aids.
Is action complete?		 System OK -
12 Replace shift solenoid #1.
Is action complete?		 Go to Step 15  -
13 Refer to Line Pressure Check Procedure  for further diagnosis of the transaxle's performance. Repair as necessary.
Is the action complete?		 Go to Step 15  -
14 Replace Powertrain Control Module (PCM). Refer to Powertrain Control Module (PCM) Replacement in Engine Controls.
Is action complete?		 Go to Step 15  -
15 Perform the DTC Confirmation Procedure.
Are any DTCs displayed on the Scan Tool?		 Go to applicable DTC table System OK
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