C0595Brake Booster Internal Power Driver Range/Performance
- Generic OBD-II code · Chassis
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- C0595 covers the power path inside the booster electronics: master switch, safety relay and the six-transistor bridge driver. GM's 2016/2019 hybrid booster switches its master switch on, off and on again at start-up and expects the voltage ratio behind it above 0.88. In GM's IBC unit the feedback behind the motor safety relay must stay above or below 80 % of supply for 50 ms, besides configuration and SPI checks of the bridge driver; XT4 and the 2023/2025 tables test the bridge driver chip at start-up. All Type A with MIL. GM bulletin 20-NA-073 (2019–20 CT6, XT5, XT6, Blazer, Acadia, Silverado, Sierra) lists C0595 with lost assist and push-through braking, fixed by BSCM software; 19-NA-202 does the same for the 2016–19 Malibu. Mitsubishi maps C18ED-04 here.
- What you may notice
- Loss of brake assist, longer and softer pedal with more force needed
- Service StabiliTrak or brake messages, traction lamp on
- Check engine lamp (requested by the brake module)
- Likely causes
- LikelyBrake module software (GM 20-NA-073, 19-NA-202)
- PossibleDefective bridge driver chip or its SPI communication
- PossibleMotor safety relay or master switch not switching correctly
- RareSupply voltage dips or poor module ground
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.