P0757: Shift Solenoid B Stuck On
The P0757 code indicates that the transmission control module (TCM) has detected a malfunction in shift solenoid B, which is stuck in the 'on' position. This solenoid controls hydraulic pressure to engage specific gears. When stuck on, it can cause incorrect gear engagement, harsh shifts, or transmission slippage. The issue is often electrical or mechanical, affecting the solenoid itself, its circuit, or the transmission fluid.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or erratic shifting
- Transmission stuck in a single gear (limp mode)
- Poor acceleration or fuel economy
2. Most Common Causes
- Shift solenoid 'B' stuck open due to internal mechanical failure
- Valve body contamination or wear causing the solenoid to remain open
- Solenoid wiring shorted to ground or battery voltage
- Corroded, wet, or physically damaged solenoid connector or harness
- Transmission control module (TCM) fault keeping the solenoid energized
- Contaminated, low, or degraded transmission fluid
3. Step-by-Step Diagnosis
Step 1: Scan the vehicle for codes and verify P0757 is present.
Step 2: Check transmission fluid level and condition; top off or replace if necessary.
Step 3: Inspect wiring and connectors for damage, corrosion, or loose connections.
Step 4: Test shift solenoid B resistance and operation using a multimeter or scan tool.
Step 5: If solenoid is faulty, replace it; if wiring is bad, repair or replace harness.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause further transmission damage. Limp mode may limit speed and gear selection.
How much does it cost to fix?▼
Repair costs range from $150 to $400, including parts and labor. Solenoid replacement is typically $50-$150, plus diagnostic fees.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.