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