P1706

P1706 is a Ford-specific code meaning the PCM saw vehicle speed above the calibrated threshold (typically 5-10 mph) while the Transmission Range Sensor was reporting Park — a physical impossibility that means either the TRS is lying about Park or the VSS/OSS is reporting phantom speed. Cheapest-first ladder: (1) Scan live data and confirm both TR position and VSS/OSS while driving — if TR shows Park during normal driving you have a TRS signal stuck on the Park step (~0.5V), and that's a sensor or harness problem, not a real concurrent-state event. (2) Inspect the shifter cable/linkage adjustment — a stretched or misadjusted shift cable can leave the trans physically in Drive while the cable-actuated TRS lever sits at the Park detent; verify by reaching under and confirming the manual valve lever position matches the column indicator at every gear ($0, 10 min). (3) Check TRS voltage steps at the PCM connector (Park ~0.5V, Reverse ~1.2V, Neutral ~2.0V, Drive ~2.8V, 2 ~3.6V, 1 ~4.4V) — if the Park step is normal at standstill but the voltage stays at 0.5V while moving, the sensor's wiper or contact set has failed open. (4) Inspect the trans-case bulkhead seal for ATF migration into the harness, which is the most common root cause that pulls the TR signal toward the Park rail. Expensive-misdiagnosis caveat: don't reprogram the PCM or replace the OSS/VSS to chase P1706 — the code's logic is anchored on the TR signal, and 9 out of 10 P1706 tickets are TRS or shift-linkage problems; the speed input is rarely wrong because it's checked against ABS wheel speeds at the CAN bus.

Vehicle-specific patterns: AODE/4R70W/4R75W in E150/E250/E350 vans (1996-2014), F150/F250 (1997-2010), Crown Vic Police Interceptor (1996-2011), and Mustang (1996-2010) throws P1706 from the same TRS contamination path as P1702 — fluid migration up the trans harness onto the TR pins. 1996-2003 Explorer/Mountaineer with the 5R55E sees P1706 specifically when the MLPS lever's Park-detent contact wears and the wiper hangs at the Park step under road vibration. 2011-2020 F150 and 2011-2017 Mustang/Expedition with the 6R80 see P1706 from the lead-frame internal harness connector cracking. P1706 also surfaces after a sloppy trans swap when the shifter cable wasn't re-adjusted — verify cable adjustment before opening the trans. Estimated repair: $45 to $850.