C0596 code meaning
Brake Booster Motor A Current Sensor Circuit Range/Performance
Chassis system Generic code C05xx codes Check engine light
What C0596 means
C0596 questions the current measurement of booster motor A itself rather than the motor. GM's 2016/2019 hybrid booster tests its overcurrent comparator at start-up by forcing minimum and maximum PWM and reading the comparator output back over a feedback line, while the voltage behind the master switch must sit near zero or near battery voltage; a hardware overcurrent flag on that line during operation also sets it (30 ms). GM's 2019 IBC unit injects zero, positive, negative and common-mode offsets into the current sense path at power-up, with the motor almost still and 7.1–18 V supply, and compares the results with their allowed bands. All Type A with MIL. Driver chips such as TI's DRV8343-Q1 short the amplifier inputs on command for this zero calibration.
C0596 at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0596
- Brake assist warning right after switching on
- Heavy brake pedal, check engine lamp on
Common causes of C0596
- Most likelyFaulty current sense amplifier or motor driver chip
- PossibleOvercurrent comparator or its feedback line not responding
- Less likelySupply voltage outside the test window during start-up
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Booster motor a current sensorBrake system control module
What each part of C0596 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 96 | The exact fault in that area. |
What to do next
- Note C0596 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about C0596
What does C0596 mean?
C0596 means "Brake Booster Motor A Current Sensor Circuit Range/Performance". C0596 questions the current measurement of booster motor A itself rather than the motor. It is a generic code, so it means the same on every make.
Is it safe to drive with C0596?
Drive gently and only to a workshop. With C0596 the car can go into limp mode (reduced power) to protect itself.
Will C0596 fail an emissions test?
C0596 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is C0596 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will C0596 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.