B2A38

Code

Generic B — Body

Steering Angle Sensor A Circuit Range/Performance

Brand: Generic

Type: B — Body

Views: UK: 4 EN: 9 RU: 4

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty steering angle sensor (AIS) or sensor module
Corroded, loose or damaged connector or wiring (open, short to ground or battery, high resistance)
Loss of reference or ground supply to the sensor
CAN/LIN communication errors or module fault (ABS, EPS, body control module)
Sensor misalignment or missing zero-point / calibration
Recent steering column/airbag/clock spring replacement not recalibrated

Symptoms

ESC/ABS/Traction Control warning light illuminated
Steering/traction control functions disabled or limited
Instrument cluster may show related body/control module warnings
Steering angle live value is implausible or jumps erratically on scan tool
Possible degraded steering assist feel or inconsistent behavior during maneuvers
Stored related communication DTCs (U-codes)

What to check

Read freeze frame and full DTC list with an OEM-capable scan tool; note accompanying codes
Record live steering angle sensor A values at center and while turning; observe for smooth, proportional change
Compare steering wheel angle to actual wheel position (if available) or to steering angle channel B (redundant)
Verify sensor supply voltage and ground at the connector (reference typically 5V and good ground)
Inspect connector and wiring for corrosion, breaks, pin damage, water intrusion or chafing; wiggle test while monitoring live data
Check for recent steering, column, airbag or clock spring repairs that require a relearn/calibration

Signal parameters

Typical reference (Vref): ~5 V (verify OEM spec)
Signal type: analog 0–5 V or differential/dual-channel/serial (many modern vehicles use CAN/LIN digital messages)
Center/zero position often near mid-supply (~2.5 V) for analog sensors; values should change smoothly with wheel rotation
Two-channel redundancy: channels should agree within a few degrees or identical digital messages
Signal should not jump, drop out, or show intermittent spikes when turning the wheel

Diagnostic algorithm

Retrieve all active and historic DTCs and freeze-frame data; note time stamps and related codes.
With a scan tool, monitor steering angle sensor A and B (if present) while slowly rotating the steering wheel from lock-to-lock. Look for smooth, proportional output and agreement between channels.
Verify supply/ground at the sensor connector: check reference voltage, signal voltage, and ground continuity to chassis. Repair any poor connections.
Visually inspect harness and connector for damage, corrosion, pin push-out, water entry, or chafe; perform wiggle tests while watching live data for intermittent faults.
If wiring and connector are good, perform or instruct manufacturer-required zero-point/initialization (steering angle sensor relearn) and clear codes, then retest.
If the fault persists and the sensor still reports out-of-range or non-linear output, substitute a known-good sensor or bench-test the unit per OEM procedure.
If a replacement sensor does not fix the issue, investigate upstream modules and CAN/LIN communication (ABS/ESP/EPS modules), and inspect for BCM or ECU errors.
After repair, perform relearn/calibration procedures and a test drive to confirm code does not return and system behavior is normal.

Likely causes

Faulty steering angle sensor
Connector corrosion, bent pins, or wiring open/short near the steering column
Missing or failed sensor zero-point calibration after repair
Loss of sensor reference voltage or poor ground
Faulty ABS/ESP/EPS module or CAN bus communication error

Fault status

⚠️ Status

Steering angle sensor A output out of expected range or outside performance parameters. Stability/traction control functions may be disabled until the fault is cleared and underlying cause corrected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours