P0708
Transmission Range Sensor Circuit Low Input
Powertrain Transmission Control Range/Position Sensor 🟡 Moderate — Fix within a week
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What This Actually Means
In plain language — no jargon

The transmission range sensor tells your engine computer what gear you've selected, but it's sending a voltage signal that's too low to read properly. Think of it like a dimmer switch stuck on the dimmest setting when it should be bright.

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Symptoms You May Notice
3 known symptoms for this code
Check Engine Light illuminated
Transmission stuck in limp mode or fails to shift properly
Engine may not start or stalls unexpectedly
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors the transmission range sensor voltage to identify selected gear position (Park, Reverse, Neutral, Drive). The sensor produces a variable voltage output based on selector position. When voltage falls below the minimum threshold, the ECU cannot reliably determine gear selection and triggers a fault.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Sensor Voltage 0.5V - 4.5V (varies by position) Below 0.2V or open circuit
Signal Integrity Stable voltage matching gear position Erratic or continuously low signal
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Battery terminals and ground connections
Clean corrosion from battery terminals and engine ground straps to restore proper voltage supply to the sensor circuit.
2
Transmission range sensor wiring harness
Inspect connector pins for corrosion, looseness, or damaged wires; reseat connector firmly at the sensor.
3
Transmission range sensor
Replace the sensor if voltage remains low after checking connections and wiring.