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Transmission Fluid Pressure (TFP) Valve Position Switch

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  1. Install Jumper Harness (J39775) to transmission 20-pin connector. Using DVOM, measure resistance between terminal "N" of transmission 20-pin connector and ground. See Figure. If resistance is less than 50 k/ohms, go to next step. If resistance is more than 50 k/ohms, go to step 3).
  2. Disconnect TFP valve position switch connector. Measure resistance between terminal "A" at TFP valve position switch and ground. See WIRING DIAGRAMS . If resistance is more than 50 k/ohms, go to step 15). If resistance is less than 50 k/ohms, replace TFP valve position switch.
  3. Measure resistance between terminal "R" of transmission 20-pin connector and ground. If resistance is more than 50 k/ohms, go to step 5). If resistance is less than 50 k/ohms, go to next step.
  4. Disconnect TFP valve position switch connector. Measure resistance between terminal "B" at TFP valve position switch and ground. See WIRING DIAGRAMS . If resistance is more than 50 k/ohms, go to step 15). If resistance is less than 50 k/ohms, replace TFP valve position switch.
  5. Measure resistance between terminal "P" of transmission 20-pin connector and ground. See Figure. If resistance is less than 50k/ohms, go to next step. If resistance is more than 50 k/ohms, go to step 7).
  6. Disconnect TFP valve position switch connector. Measure resistance between terminal "C" at TFP valve position switch and ground. See WIRING DIAGRAMS . If resistance is more than 50 k/ohms, go to step 15). If resistance is less than 50 k/ohms, replace TFP valve position switch.
  7. Start engine and allow to idle. Set parking brake. Place gear selector in "D" position. Measure resistance between terminal "R" of transmission 20-pin connector and ground. If resistance is less than 200 ohms, go to next step. If resistance is more than 200 ohms, go to step 14).
  8. With gear selector in "D" position, measure resistance between terminal "P" of transmission 20-pin connector and ground. If resistance is less than 200 ohms, go to next step. If resistance is more than 200 ohms, go to step 14).
  9. Place gear selector in "1" (low gear) position. Measure resistance between terminal "N" of transmission 20-pin connector and ground. If resistance is less than 200 ohms, go to next step. If resistance is more than 200 ohms, go to step 14).
  10. With gear selector in "1" (low) position, measure resistance between terminal "P" of transmission 20-pin connector and ground. If resistance is more than 50 k/ohms, go to next step. If resistance is less than 50 k/ohms, go to step 15).
  11. Place gear selector in "R" (Reverse) position. Measure resistance between terminal "N" of transmission 20-pin connector and ground. If resistance is less than 200 ohms, go to next step. If resistance is more than 200 ohms, go to step 15).
  12. With gear selector in "R" (Reverse) position, measure resistance between terminal "P" of transmission 20-pin connector and ground. If resistance is more than 50 k/ohms, go to next step. If resistance is less than 50 k/ohms, go to step 15).
  13. Place gear selector in "3" (3rd gear) position. Measure resistance between terminal "R" of transmission 20-pin connector and ground. If resistance is more than 50 k/ohms, go to next step. If resistance is less than 50 k/ohms, go to step 15).
  14. Disconnect TFP valve position switch connector. Check for open in switch circuits. Repair as necessary, then go to next step. If circuits are okay, replace TFP valve position switch.
  15. Check for short or high resistance in TFP valve position switch circuits. Check for poor connections at transmission 20-pin connector and at TFP valve position switch. Check for bent, backed out or damaged terminals, or poor terminal tension. If diagnosing for intermittent condition problem, wiggle wiring harness while observing scan tool for change in value. If short or high resistance is found, verify repair, then repeat test procedure. If short or high resistance is not found, check for open or short to ground in circuits between TFP valve position switch and VCM. Replace wiring harness as necessary. If circuits are okay, replace TFP valve position switch.
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