OBD-II code · Chassis
C0637 Brake Pressure Sensor G Circuit Low
Brake pressure sensor G signal voltage below expected range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with C0637?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySignal wire shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Usually unaffected
- Parts involved
- Brake Pressure Sensor G
Related codes
- C053EBrake Pressure Sensor A Circuit Low
- C0542Brake Pressure Sensor B Circuit Low
- C059FBrake Pressure Sensor E Circuit Low
- C05C6Brake Pressure Sensor F Circuit Low
- C063BBrake Pressure Sensor H Circuit Low
- C063FBrake Pressure Sensor J Circuit Low
- C0643Brake Pressure Sensor K Circuit Low
- C0647Brake Pressure Sensor L Circuit Low
- C064BBrake Pressure Sensor M Circuit Low
- C064FBrake Pressure Sensor N Circuit Low
- C0634Brake Pressure Sensor A/B Correlation
- C0635Brake Pressure Sensor G Circuit/Open
- C0636Brake Pressure Sensor G Circuit High
- C0638Brake Pressure Sensor G Range/Performance
- C0639Brake Pressure Sensor H Circuit/Open
- C063ABrake Pressure Sensor H Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.