P0708
OBD-II Diagnostic Code
Severity: ModerateWhat Does This Error Mean?
P0708 means the transmission range sensor voltage is abnormally high. This typically indicates an open circuit — the sensor is disconnected or has failed internally. Check the sensor connector and wiring.
Affected Models
- All OBD-II vehicles with automatic transmissions (1996+)
Common Causes
- Sensor connector disconnected
- Open circuit in sensor wiring
- Sensor internal failure
- Corroded ground connection
How to Fix It
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Check that the sensor connector is plugged in.
A disconnected sensor produces maximum voltage (high input). Reconnect if loose.
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Inspect wiring for breaks.
Trace the wires from sensor to ECM. Look for cuts, chafing, or heat damage.
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Replace the sensor if it is internally open.
Test with a multimeter — an open circuit reading means the sensor is bad.
Frequently Asked Questions
Can P0708 cause the car to not start?
Possibly. If the ECM reads an invalid gear position, the neutral safety logic may prevent starting.
Is high input the same as the sensor reading high gear?
No. High input refers to high voltage on the sensor circuit — usually meaning an open (disconnected) circuit, not a gear position.