P0706Powertrain
Powertrain · SAE
Transmission Range Sensor Circuit Range/Performance
Meaning
The TCM has detected that the transmission range sensor (TRS) signal is implausible or incoherent, without being fully absent as in P0705. Typical examples include multiple positions active simultaneously, a signal that oscillates between positions without driver input, or a value that does not correspond to any valid gear position. The sensor is electrically present but provides unreliable data.
Common causes
- Worn, contaminated, or mechanically misadjusted transmission range sensor (TRS)
- Oxidized or intermittent internal contacts within the TRS
- Excessive play or wear in the mechanical linkage between the selector lever and TRS
- Partial short circuit or high resistance in the TRS wiring
- TRS connector with intermittent pins or moisture contamination
- Internal TRS failure generating multiple or erratic output signals
Symptoms
- Engine or transmission warning lamp illuminated
- Erratic automatic transmission behavior with unexpected unprompted shifts
- PRNDL indicator displaying incorrect positions or changing on its own
- Transmission failing to recognize Park or Neutral
- Difficult or impossible engine start in Park or Neutral
- Fault code may appear intermittently
Severity
Medium to high severity: an unreliable TRS signal can cause unpredictable transmission behavior and dangerous driving conditions; timely diagnosis is required.
What to do
- Check the mechanical adjustment of the TRS and its linkage to the selector lever; correct any play or misalignment
- Inspect the TRS connector for contamination, oxidation, or intermittent pins; clean and reseat
- Use a scan tool to monitor the TRS signal in real time while slowly moving the selector through all positions, looking for erratic readings or overlapping position signals
- Measure TRS output voltages in each position with a multimeter and compare against specification
- Replace the TRS if testing confirms an erratic or out-of-specification signal