P0755 Fault Code in Nissan: Causes, Symptoms, and Fixes

The P0755 diagnostic trouble code (DTC) means the Powertrain Control Module (PCM) has detected a malfunction in Shift Solenoid ‘B’ in the automatic transmission. This solenoid helps control gear shifting by regulating hydraulic pressure.

Symptoms of P0755:

1. Hard or delayed gear shifting
2. Transmission stuck in 2nd or 3rd gear (limp mode)
3. Check Engine Light ON
4. Poor fuel efficiency
5. Engine may rev high before shifting

Common Causes:

1. Faulty shift solenoid ‘B’- Mechanically stuck or electrically open/shorted
2. Dirty or low transmission fluid – Affects solenoid function
3. Damaged transmission wiring harness – Corrosion or short circuits
4. Faulty TCM/PCM – Rare, but possible cause
5. Internal valve body issue – Wear or debris inside transmission

Recommended Fixes:

1. Check & replace transmission fluid (make sure it’s clean and full)
2. Inspect and clean solenoid wiring/connectors
3. Replace Shift Solenoid B
4. Check valve body for sticking valves or debris
5. Scan and clear code, perform test drive

Solenoid B Position (May vary by manufacturer):

1. Toyota U-series → Solenoid B = SL2
2. Hyundai/Kia → Inside valve body, attached to main harness
3. Honda → Integrated into shift control body
4. Ford/GM → Part of solenoid pack or EPC module