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. 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.
Medium severity. Can I keep driving?Drive gently to a repair shop. If it slips, you hear clunks, or it loses its gears, do not keep driving.
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
Most likely causes
- Sensor connector off or signal/ground wire open
- Signal wire shorted to voltage
- Sensor faulty internally
- Poor sensor or transmission ground
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P0708 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 7: Transmission
- 08: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0708?
Drive gently to a repair shop. If it slips, you hear clunks, or it loses its gears, do not keep driving.
What causes code P0708?
The most common causes are: sensor connector off or signal/ground wire open; signal wire shorted to voltage; sensor faulty internally.
Related codes
- P0705Transmission Range Sensor A Circuit (PRNDL Input)
- P0706Transmission Range Sensor A Circuit Range/Performance
- P0707Transmission Range Sensor A Circuit Low
- P0709Transmission Range Sensor A Circuit Intermittent
- P2803Transmission Range Sensor B Circuit High
- P0643Sensor Reference Voltage A Circuit High
Sources
- law.cornell.edu: 13 CCR 1968.2
- gsi.ext.gm.com: 20OBDG03A Diagnostics
- newtonnet.co.uk: fordobd2012
- saabwisonline.com: dtc p0706 p0708
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.