Input/Turbine Speed Sensor Range/Performance Problem

The input speed sensor measures how fast the engine and transmission are working together. If it's not working right, the vehicle might shift poorly or have no response in gear.

The computer expects a certain frequency signal from the input speed sensor, indicating the turbine speed in RPM. If the signal is out of the expected range (usually between 200-7000 RPM) or intermittent, you get this code.

Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.

1. 11. Check the input speed sensor wiring and connector for damage or corrosion. If damaged, repair/replace. Decision: If physical damage is found, repair and retest; if not, proceed to step 2.
2. 22. Measure the input speed sensor's voltage output (should be near 0.5 to 5 volts while spinning the sensor). If out of range, replace the sensor. Decision: If voltage is correct, proceed to step 3.
3. 33. Inspect the transmission fluid level and condition. Low or dirty fluid can cause sensor issues. Decision: If fluid is low, refill and retest; if fluid is good, proceed to step 4.
4. 44. Scan for other related codes (e.g., P0720, P0721) and check TCM functionality. If other codes are present, address them first. Decision: If no other codes are present, proceed to step 5.
5. 55. If all checks are good, the issue may lie within the transmission itself or the TCM; further diagnostics on those components may be necessary.

• Faulty input speed sensor
• Damaged wiring or connector
• Low transmission fluid levels
• Faulty transmission control module (TCM)
• Internal transmission issues

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