P0706: Transmission Range Sensor 'A' Circuit Range/Performance
May cause incorrect gear identification, improper or no shifting, and potential safety concerns starting outside park/neutral
Overview
P0706 indicates a range or performance fault in the Transmission Range Sensor (also known as neutral safety/PRNDL switch) circuit. It triggers when sensor output voltage does not fall within expected parameters for gear selection, affecting transmission operation.
Common Symptoms
- Check Engine Light illumination
- Erratic or failed gear shifts
- Inability to start in park/neutral
- Transmission stuck in one gear or limp mode
- Unexpected gear selection
Most Common Causes
Sensor fails to report correct gear position voltage range
Open circuits, shorts, or poor connections lead to out-of-range signal
Incorrect sensor indexing leads to incorrect voltage outputs
Rare but possible unit input driver failure or corrupted calibration
Internal mechanical/hydraulic issues may indirectly affect readings
Diagnostic Steps
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Connect OBD-II scanner and verify P0706 with live dataExpected: Sensor output voltages change logically when shifting through gearsInterpretation: Consistent out-of-range data confirms sensor circuit performance fault
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Visually inspect transmission range sensor, wiring harness, and connectorsExpected: No damaged, corroded, or disconnected wiringInterpretation: Presence of damage suggests wiring repair before further testing
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Test sensor voltage at TRS while moving gear selectorExpected: Voltage values reflect expected ranges for Park/Neutral/DriveInterpretation: Deviations indicate sensor or circuit issue
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Check for correct sensor alignment/indexing per manufacturer specExpected: Sensor aligned so gearbox manual valve and sensor correlateInterpretation: Misalignment can trigger false performance errors
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If wiring and sensor pass tests, evaluate TCM/PCM inputsExpected: Reference and signal circuits functioning with correct voltagesInterpretation: Faulty TCM/PCM may need specialized diagnostics or replacement
Repair Solutions
Often primary fix; calibration/alignment may be required
Fix shorts, corrosion, open circuits
Simple adjustment if misaligned
Rare; requires professional service
Common Misdiagnoses
Avoid these common diagnostic mistakes:
- Engine misfire or driveline fault misattributed instead of transmission range sensor issue
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