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Diagnostic Procedures

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  1. Ensure transmission fluid level is correct. Connect scan tool to DLC. Turn ignition switch to ON position. DO NOT start engine. Using scan tool, record freeze frame and failure records for reference. Data will be lost when DTCs are cleared later in this test.
  2. Start engine and let idle. Apply parking brake. While observing scan tool, shift transmission into each gear position. If gear position matches Transmission Fluid Pressure (TFP) position switch A/B/C display on scan tool, go to next step. If gear position does not match Transmission Fluid Pressure (TFP) position switch A/B/C display on scan tool, diagnose TFP position switch. Switch is also referred to as Pressure Switch Assembly (PSA). See COMPONENT TESTS . Also see DTC 1810.
  3. Drive vehicle in 1st, 2nd and 3rd gear with throttle angle more than 25 percent. Hold vehicle speed above 7 MPH for more than 2 seconds in each specified gear range. Use snapshot mode on scan tool to record transmission gear ratio for each commanded gear range. If gear ratios are within parameters for each specified gear range, see DIAGNOSTIC AIDS. If gear ratios are not within parameters for each specified gear range, perform line pressure test. See HYDRAULIC PRESSURE TESTS in AUTO TRANS OVERHAUL article.
  4. If line pressure is not within specifications, see TROUBLE SHOOTING in AUTO TRANS OVERHAUL article for diagnosis. If line pressure is within specifications, remove transmission oil pan and check for debris in pan or fluid contamination. Check for sticking shift solenoids or apply pistons. Repair as necessary, then go to next step.
  5. After repair is complete, select DTC on scan tool. Select "Clear Info" function. Drive vehicle in 1st, 2nd and 3rd. VCM must detect a valid gear range versus commanded gear for 10 seconds. Select "Specific DTC" and enter DTC "P0730". If DTC P0730 is not present, repair is complete. If DTC P0730 is still present, repeat test.
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