P1911: Definitions depend on the manufacturer — what it means, the affected system and what to check before replacing parts.
Meaning, symptoms, causes and checks
VFS B Pressure Output Failed Low. Source catalogue definition; confirm applicability using vehicle service information.
Affected system: Powertrain
Symptoms
- Check engine light illumination
- Harsh or erratic gear shifting
- Transmission stuck in a specific gear
- Noticeable loss of vehicle power
- Reduced fuel efficiency
Possible causes
- Faulty VFS B solenoid valve
- Short circuit or open wiring in the solenoid control circuit
- TCM internal failure
- Contaminated or low transmission fluid
- Mechanical blockage in the valve body
What to check
- Inspect the wiring harness and connectors for signs of corrosion or damage
- Check transmission fluid level and condition for debris or burnt odor
- Measure the resistance of the VFS B solenoid using a multimeter
- Test for voltage signal at the solenoid connector during command activation
- Verify the integrity of the transmission control module wiring circuits
Also written as: P1911-00, P191100 (some scan tools add the fault-type byte, e.g. -00).