What does code P1578 mean?

Q: What does code P1578 mean?

BBV Sensor Circuit Low Vacuum. P1578 on Chrysler vehicles means the powertrain control module (PCM) has detected a low-vacuum condition in the brake booster vacuum (BBV) sensor circuit, indicating that the sensor signal is reporting less vacuum than expected during engine operation. The PCM compares the BBV sensor voltage to a calculated vacuum model based on engine load, throttle position, and RPM, and sets this code when the signal falls below the low-vacuum threshold for a calibrated time.

DTC codes / Chrysler codes / P1578

P1578 · ChryslerBBV Sensor Circuit Low Vacuum

P1578 on Chrysler vehicles means the powertrain control module (PCM) has detected a low-vacuum condition in the brake booster vacuum (BBV) sensor circuit, indicating that the sensor signal is reporting less vacuum than expected during engine operation. The PCM compares the BBV sensor voltage to a calculated vacuum model based on engine load, throttle position, and RPM, and sets this code when the signal falls below the low-vacuum threshold for a calibrated time.

SystemPowertrain

Code typeChrysler specific

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

Guidance is general and written for Chrysler vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.