Intermediate Shaft Speed Sensor B Circuit
Code P2745 indicates the transmission control module has detected a problem with the Intermediate Shaft Speed Sensor B circuit, which monitors transmission internal shaft speed for proper gear shifting. This sensor provides critical feedback for transmission shift timing and quality; when the circuit fails, the transmission cannot accurately determine shaft speed, resulting in shifting problems and transmission stress.
What You Might Notice
- Hard or delayed gear shifts
- Multiple warning lights on instrument panel
- Erratic engine speed or surging
- Poor vehicle acceleration and driveability
- Transmission may enter limp mode or failsafe shift pattern
Most Common Causes
- 1
Defective Intermediate Shaft Speed Sensor
The sensor itself has failed or become damaged, preventing accurate speed signal transmission to the TCM. This is the most common cause of this code.
- 2
Wiring or Connector Issues
Damaged, corroded, or loose wiring and connectors between the speed sensor and transmission control module prevent proper signal flow. This includes broken pins or water intrusion into connectors.
- 3
Low or Dirty Transmission Fluid
Contaminated or insufficient ATF can cause sensor malfunction and affect transmission solenoid operation. Dirty fluid may contain particles that interfere with sensor accuracy.
- 4
Internal Transmission or ECM/TCM Fault
Related shift solenoids, input/output shaft sensors, or the transmission control module itself may be damaged, preventing proper circuit communication and sensor signal processing.
How to Diagnose It
- 1
Check Defective Intermediate Shaft Speed Sensor — The sensor itself has failed or become damaged, preventing accurate speed signal transmission to the TCM. This is the most common cause of this code.
- 2
Check Wiring or Connector Issues — Damaged, corroded, or loose wiring and connectors between the speed sensor and transmission control module prevent proper signal flow. This includes broken pins or water intrusion into connectors.
- 3
Check Low or Dirty Transmission Fluid — Contaminated or insufficient ATF can cause sensor malfunction and affect transmission solenoid operation. Dirty fluid may contain particles that interfere with sensor accuracy.
- 4
Check Internal Transmission or ECM/TCM Fault — Related shift solenoids, input/output shaft sensors, or the transmission control module itself may be damaged, preventing proper circuit communication and sensor signal processing.
How to Fix It
- 1
Inspect and Replace Intermediate Shaft Speed Sensor
Locate the intermediate shaft speed sensor (typically inside or near the transmission), inspect for damage or corrosion, and replace if defective. Test with a multimeter for proper resistance and voltage signals before replacement to confirm fault.
- 2
Check and Repair Wiring and Connectors
Inspect all wiring and connectors between the speed sensor and TCM for corrosion, damage, bent pins, or loose connections. Repair or replace damaged wires and connectors, ensuring proper seating and crimped connections.
- 3
Change Transmission Fluid and Filter
Drain and replace the automatic transmission fluid and filter with the manufacturer-recommended ATF type. Dirty or low fluid can cause sensor malfunction and should be addressed as preventive maintenance.
- 4
Diagnose Related Transmission Components
If the above fixes do not resolve the code, have a professional scan and test related shift solenoids, input/output shaft sensors, and the transmission control module (TCM) for internal faults using specialized diagnostic equipment.
Need a deeper diagnosis?
Search for related repair guides or browse by system.