What P0708 means
The transmission range sensor (selector or multifunction switch, PRNDL) reports the selected range; it may be a multi-contact switch with a bit pattern per position, an analog sensor with two opposing voltages adding up to 5 V, or a contactless PWM sensor.
How the engine computer detects it
Its second channel has its own codes (P2801–P2805). P0708 means the sensor A signal is too high – a short to voltage or, depending on the circuit, an open line pulled up. GM's T87A transmission module flags a PWM duty cycle above 91.2 % for 1.8 s within 2.25 s, lamp in the first trip; Ford flags a duty cycle above 90 %, an analog sensor above 4.8 V for 5 s, a dual-analog channel above 4.84 V for 200 ms, and explicitly an open circuit on its digital sensor (all switches open, e.g. unplugged); Saab's 9-5 (9650) above 4.87 V for 100 ms twice, with 2nd gear held and a restart interlock.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine and/or transmission warning lamp
- Transmission limp mode, fixed gear, harsh shifts
- Starting problems in P/N or start interlock
- Wrong gear indication, reversing light not working
Common causes
- Sensor connector off or signal/ground wire open Most likely
- Signal wire shorted to voltage Possible
- Sensor faulty internally Possible
- Poor sensor or transmission ground Less likely
How to diagnose P0708
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: transmission range sensor, sensor wiring, transmission control module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 7
- Transmission
- 08
- Specific fault
Questions drivers ask
Can I drive with code P0708?
If the car shifts normally, drive gently to a shop. If it's stuck in one gear, slips, shifts harshly or won't move out of Park, don't drive it: have it towed.
Will my car pass an emissions inspection with P0708?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.