P0708 critical

Transmission Range Sensor Circuit High Input

The P0708 code means the vehicle's onboard diagnostic system has detected: Transmission Range Sensor Circuit High Input. This is a critical severity code.

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Keep driving?: Short distances only
DIY difficulty: moderate
Estimated cost: $100 - $350 (parts and labor)

Check Your Fluid First

ANCEL AD310 OBD-II Scanner

Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.

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Read Transmission Codes

LAUNCH CRP123X (Reads All Systems)

Basic scanners only read engine codes. This reads transmission, ABS, and airbag too.

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Common Symptoms

Check Engine Light illuminated
Erratic transmission shifting
Vehicle starts in gear other than Park/Neutral
Dashboard gear display incorrect

Probable Causes (Ranked by Likelihood)

Faulty transmission range sensor Very High
Open ground wire to range sensor High
Signal wire shorted to voltage Moderate
TCM input circuit pull-up fault Low

Step-by-Step Diagnostic Procedure

Check range sensor voltage -- above 4.5V indicates high input fault
Verify ground wire continuity from sensor to TCM
Check for chafed signal wire contacting a voltage source
Disconnect sensor and check if voltage drops at TCM connector
Replace sensor if wiring is confirmed good

Frequently Asked Questions

Can I drive with code P0708?

Drive short distances only. High input means the TCM sees an incorrect gear position, leading to unpredictable shifting behavior.

What is the difference between P0707 and P0708?

P0707 indicates low voltage input (below range) and P0708 indicates high voltage input (above range). Both point to the transmission range sensor or its circuit.

Can I adjust the range sensor instead of replacing it?

Sometimes. If the sensor has shifted out of alignment, readjusting it to match the shift positions can resolve the code. However, if the sensor has failed internally, replacement is needed.