C1A14

Code

Generic C — Chassis

Yaw Rate Sensor Circuit High Input

Brand: Generic

Type: C — Chassis

Views: UK: 12 EN: 16 RU: 16

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Causes

Short to battery/constant 12V on the yaw sensor signal wire
Open or high-resistance ground or reference supply to the sensor
Damaged or corroded sensor connector or wiring (chafing, water ingress)
Faulty yaw rate (gyro) sensor
Intermittent or poor connection at ABS/ESC control module connector
Internal fault in ABS/ESC control module or harness splice

Symptoms

ABS/ESC/Traction control warning lamp illuminated
Stability control and/or traction control disabled or partially inoperative
Loss of electronic stability assist or reduced functionality during braking/maneuvering
Yaw rate reading abnormally high or pegged on a diagnostic scan tool
Possible fault memory stored with freeze frame data
Vehicle may enter reduced handling or limp/stability mode under some conditions

What to check

Read and record all stored codes and freeze-frame data with a capable scan tool (ABS/ESC module)
Check live data: yaw rate sensor value at rest (should be ~0 deg/s), then during slow steering — look for pegged/high values
Inspect sensor connector and wiring for corrosion, damage, pin push-out, or water intrusion
Visually inspect harness routing near suspension, steering column, and chassis for chafing or pinch points
Back-probe sensor supply (VB or 12V), reference (if present) and ground with ignition ON — confirm proper voltages and grounds
Measure signal voltage at the sensor and at the module connector to find differences (open circuit)

Signal parameters

Analog sensors: typical zero-rate output ≈2.5 V (± small offset); high-input condition often >4.5 V or pegged near VB
Digital/CAN MEMS sensors: yaw rate data typically reported in deg/s (common ranges ±200–±500°/s); a high-input condition may show pegged max value or invalid flag
Supply voltage (VB) normally ≈9–16 V (vehicle 12V system); reference/logic supply typically 5 V or 3.3 V depending on manufacturer
Sensor ground near 0 Ω to chassis; continuity
Expected sensitivity (example): 0.01–0.05 V per °/s (manufacturer-specific) — consult service data for exact values

Diagnostic algorithm

Connect an advanced scan tool to ABS/ESC module. Record C1A14 and any related codes; note freeze-frame and live yaw-rate readings at key states (rest, steering input).
Visually inspect sensor, connector, and harness for damage, corrosion, or water. Repair any obvious wiring damage and retest.
With ignition ON (engine off) back-probe at the sensor connector: verify sensor supply (VB), ground integrity, and signal voltage. Compare to expected zero-rate value (often ~2.5 V for analog). If signal is >4.5 V or at battery voltage, suspect short to VB or sensor failure.
If sensor supply or ground is out of tolerance, trace and repair wiring (check fuses, relays, grounds). Re-check voltages after repairs.
If voltages at sensor are correct but module sees a high signal, back-probe at the ABS/ESC module connector (with harness exposed) to compare signal there vs at sensor. If signal high at module but normal at sensor, suspect module or harness splice/connector between.
For open/short concerns, perform continuity and resistance checks between sensor pins and module pins (battery disconnected). Repair broken/chafed wires, replace harness or repair splices as needed.
If wiring and connectors are good and sensor supply/ground are correct but the signal remains high, swap the yaw rate sensor with a known-good unit (if available) or replace the sensor. After replacement, clear codes and road-test.
If a new sensor does not clear the fault and wiring is good, consider ABS/ESC control module input circuit fault — consult manufacturer service info for module bench tests or replacement procedures.
After repair, clear codes and perform a calibration/initialization procedure if required (seat calibration/ESC learn). Verify with road test and confirm code does not return.
Safety note: if stability control is disabled, advise careful driving and avoid high-speed or hazardous maneuvers until the system is restored.

Likely causes

Signal wire shorted to Vb or ignition 12V
Corroded pin or bent terminal in sensor connector allowing high voltage reading
Yaw sensor internal failure causing output to rail high
Poor ground or missing sensor reference voltage causing comparator to read a high relative value
Faulty ABS/ESC module input stage (less common)