Common Symptoms
- Check Engine Light illuminated
- Transmission fails to shift or shifts erratically
- Speedometer shows zero or erratic readings while driving
- Vehicle stuck in limp mode or single gear
- Harsh or delayed shifting between gears
- No overdrive engagement
Most Likely Root Causes
- Failed input speed sensor
- Damaged or broken wiring harness to input speed sensor
- Corroded or loose electrical connector at sensor
- Internal transmission mechanical damage affecting sensor tone ring
- Faulty transmission control module
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Component Location
Input speed sensor is typically mounted on the transmission case near the torque converter or input shaft.
Manufacturer Notes
Some manufacturers require transmission fluid level verification and quality inspection as sensor readings can be affected by low fluid.
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