C0161 code meaning
ABS/TCS Brake Switch Circuit
What C0161 means
C0161 is outside the accessible J2012 tables but well documented at GM. Service data for the later Saab 9-5 and the 9-4X define it as an implausible ABS brake switch signal: the EBCM receives the pedal-applied message from the body module and compares it with brake pressure and vehicle motion. The 9-4X sets it after four starts to over 40 km/h without any switch change, or when the pedal reads applied for 360 s above 20 km/h with less than 15 bar; the 9-5 uses 122 s and 6.2 bar plus a check for more than 15 bar for 2 s with the pedal released. GM bulletin PIT5181A for 2012–2014 full-size trucks and SUVs links C0161 and C0277 to a loose terminal in connector X205. Hill start assist may be disabled; braking while accelerating can also set it.
C0161 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.3 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of C0161
- Service stability or traction message
- Cruise control or brake lights may misbehave
- Hill start assist unavailable
Common causes of C0161
- Most likelyBrake pedal position sensor or switch out of adjustment
- PossibleLoose or backed-out terminal in the pedal sensor wiring (GM X205)
- Less likelyBrake applied while accelerating (left-foot braking)
- Less likelyBrake pressure sensor reading that contradicts the pedal signal
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Brake light switchABS control moduleTcs control module
What each part of C0161 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 61 | The exact fault in that area. |
What to do next
- Note C0161 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 C0161
What does C0161 mean?
C0161 means "ABS/TCS Brake Switch Circuit". C0161 is outside the accessible J2012 tables but well documented at GM. It is a generic code, so it means the same on every make.
Is it safe to drive with C0161?
C0161 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will C0161 fail an emissions test?
C0161 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 C0161 to fix?
Difficulty: easy. A typical repair takes 0.3 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will C0161 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.