Transmission range sensor or switch faulty or out of adjustment; Damaged, chafed or corroded wiring to the range sensor, including open circuit or short to voltage; Loose, corroded or water-damaged connector at the sensor or control unit; Selector linkage or cable misadjusted or worn, so the sensor does not match the lever position; Low or contaminated transmission fluid affecting an internal sensor or switch assembly (depends on gearbox design); Faulty powertrain or transmission control module.

P0708

Transmission Range Sensor A Circuit High.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
7: AreaTransmission
08: FaultThe specific fault in that area

What it means

P0708 means the powertrain control module or transmission control module has detected a high voltage or signal in the transmission range sensor 'A' circuit. This sensor (also called the PRNDL, gear selector or neutral safety switch input) tells the control unit which gear position is selected. The code sets when the signal sits above the expected range, which can point to a short to voltage, an open circuit, or a faulty sensor.

Symptoms

Warning light on, possibly with a transmission or gearbox warning message
Gear selector position shown incorrectly on the dash, or not shown at all
Engine will not start, or starts in more than one selector position
Harsh, delayed or erratic gear changes
Gearbox stuck in one gear (limp mode)
Reversing lights not working correctly

Possible causes

Transmission range sensor or switch faulty or out of adjustmentlikely
Damaged, chafed or corroded wiring to the range sensor, including open circuit or short to voltagelikely
Loose, corroded or water-damaged connector at the sensor or control unitlikely
Selector linkage or cable misadjusted or worn, so the sensor does not match the lever positionpossible
Low or contaminated transmission fluid affecting an internal sensor or switch assembly (depends on gearbox design)possible
Faulty powertrain or transmission control modulerare

How to diagnose

Read all stored and pending codes and note the freeze frame data, then check for related codes such as other range sensor circuit faults or speed sensor codes
Compare the selector position shown on live data with the actual lever position in each gear (P, R, N, D and any manual positions)
Visually inspect the range sensor, its connector and the wiring for damage, oil contamination, corrosion or water ingress
Check the selector linkage or cable for wear, looseness and correct adjustment against the manufacturer's procedure
Check the transmission fluid level and condition where the gearbox has a dipstick or a specified check procedure
Using the wiring diagram for the model, check the sensor supply, signal and earth for open circuits, shorts to voltage and correct voltage as the selector is moved
Test the sensor itself against the manufacturer's specification for the gearbox fitted
Only after the wiring and sensor are proven good, consider the control unit and check for any applicable software updates

How to fix

Repair or replace damaged wiring and clean or replace faulty connectors
Replace the transmission range sensor and set it up or adjust it to the manufacturer's procedure
Adjust or replace the selector cable or linkage
Correct the transmission fluid level or service the fluid as specified for the gearbox
Replace or reprogram the control unit only if it is confirmed faulty, or if an outdated calibration is a known cause for that model

Can I keep driving?

Medium severity

The car may be driveable, but gear selection and starting can become unreliable and the gearbox may go into limp mode. Get it checked soon, and avoid driving if it will not hold the correct gear or the starting is erratic.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.