Input/Turbine Speed Sensor "B" Circuit
The Input/Turbine Speed Sensor A circuit is not communicating properly with the PCM, preventing accurate transmission fluid speed measurement. This causes the transmission control module to lose critical data needed for smooth shifting and torque converter operation.
What You Might Notice
- Transmission shifting harshly or roughly
- Transmission enters limp mode with reduced power
- Check Engine Light illuminated
- Delayed or erratic gear changes
- Possible loss of overdrive function
Most Common Causes
- 1
Defective Input Speed Sensor
The sensor itself has failed electrically or mechanically, preventing proper signal transmission to the PCM. This is the most common cause of this code.
- 2
Damaged Reluctor Ring or Shaft
Wear, breakage, or damage to the reluctor ring or transmission shaft disrupts the magnetic signal the sensor relies on to read speed accurately.
- 3
Loose or Damaged Wiring and Connectors
Corroded, burned, or loose wiring connections at the sensor or PCM prevent proper electrical signal transmission between components.
- 4
Faulty Torque Converter
A malfunctioning torque converter can cause speed measurement inconsistencies that trigger this code, though less common than sensor failure.
How to Diagnose It
- 1
Check Defective Input Speed Sensor — The sensor itself has failed electrically or mechanically, preventing proper signal transmission to the PCM. This is the most common cause of this code.
- 2
Check Damaged Reluctor Ring or Shaft — Wear, breakage, or damage to the reluctor ring or transmission shaft disrupts the magnetic signal the sensor relies on to read speed accurately.
- 3
Check Loose or Damaged Wiring and Connectors — Corroded, burned, or loose wiring connections at the sensor or PCM prevent proper electrical signal transmission between components.
- 4
Check Faulty Torque Converter — A malfunctioning torque converter can cause speed measurement inconsistencies that trigger this code, though less common than sensor failure.
How to Fix It
- 1
Inspect and Replace Input Speed Sensor
Locate the input speed sensor on the transmission, test it with an ohmmeter for proper resistance values, and replace if faulty. Verify the new sensor is installed at the correct depth.
- 2
Check Wiring and Connectors
Inspect the sensor wiring harness and connectors for corrosion, damage, or loose connections. Clean corroded contacts with electrical contact cleaner and repair or replace damaged wiring.
- 3
Inspect Reluctor Ring and Transmission Shaft
Remove the transmission pan and inspect the reluctor ring and input shaft for cracks, wear, or damage. Replace the shaft assembly if damage is found.
- 4
Test and Replace Torque Converter if Needed
Have the torque converter tested for proper operation. If faulty, the transmission may need to be serviced or the torque converter replaced to restore proper speed sensing.
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