Powertrain, generic · Transmission

P0708 Transmission Range Sensor A Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Sensor connector off or signal/ground wire open
Signal wire shorted to voltage
Sensor faulty internally
Poor sensor or transmission ground

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

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–600
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

transmission range sensorsensor wiringtransmission control module

Related codes

P0705P0706P0707P0709P2803P0643

References: law.cornell.edu, gsi.ext.gm.com, newtonnet.co.uk, saabwisonline.com.