OBD-II Code
P1702
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$45–$850
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
P1702 is a Ford-specific code meaning the Transmission Range Sensor (TRS, also called MLPS on earlier gearboxes) signal went intermittent — the PCM saw the voltage drop out of all six valid range bands momentarily, then return.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureP1702 is a Ford-specific code meaning the Transmission Range Sensor (TRS, also called MLPS on earlier gearboxes) signal went intermittent — the PCM s…
P1702 is a Ford-specific code meaning the Transmission Range Sensor (TRS, also called MLPS on earlier gearboxes) signal went intermittent — the PCM saw the voltage drop out of all six valid range bands momentarily, then return. This is almost always wiring or connector, not the sensor itself.
Cheapest-first ladder
- (1) Wiggle-test the trans harness at the TRS connector with KOEO and the scan tool watching live TR voltage — a voltage spike or dropout during wiggle confirms harness/connector fault ($0, 15 min).
- (2) Pull the TRS connector and inspect for the classic Ford patterns: green corrosion on the pins, fluid wicking from the case-side seal, or backed-out pins from a prior shop disconnecting under load.
- (3) Voltage-step verification — on the TRS signal wire you should see clean steps at roughly 0.5V (Park), 1.2V (Reverse), 2.0V (Neutral), 2.8V (Drive), 3.6V (2), 4.4V (1); anything outside +/- 0.15V of those targets at the connector is a sensor problem, anything inside spec at the connector but wrong at the PCM is a harness problem.
- (4) Check the TRS ground reference — a corroded ground stud on the trans bellhousing will float every voltage step upward and set P1702 intermittently as engine bay temperature changes.
- Expensive-misdiagnosis caveat: don't replace the TRS without first inspecting the trans-case bulkhead seal — fluid migrating through the bulkhead saturates the harness jacket and travels up the wires by capillary action, contaminating the body-side connector; replacing only the sensor leaves the contamination path open and the code returns in 200-500 miles.
Vehicle-specific patternsAODE/4R70W/4R75W in E-series vans (1996-2014), F150/F250 (1997-2010), Crown Vic Police Interceptor (1996-2011), and Mustang (1996-2010) commonly thro…
- 1996-2014AODE/4R70W/4R75W in E-series vans , F150/F250 (1997-2010), Crown Vic Police Interceptor (1996-2011), and Mustang (1996-2010) commonly throws P1702 from a corroded body-side TRS connector after exposure to road salt and trans-cooler line drips — the connector lives at the LH side of the trans case and gets blasted by wheel spray.
- 2011-2020F150 and 2011-2017 Mustang/Expedition with the 6R80 see P1702 almost exclusively from the internal lead-frame connector cracking and wicking ATF onto the contacts; Ford's published guidance is lead-frame replacement, not standalone TRS replacement.
- 1996-2003Ford Explorer/Mountaineer with the 5R55E throws P1702 from a different but related path — the MLPS lever's internal wiper contacts wear flat at the Park detent and cause dropouts only at standstill.
Estimated repair$45 to $850.
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