Code
C0240
Generic
C — Chassis
Steering Angle Sensor Circuit Malfunction
Views:
UK: 9
EN: 19
RU: 19
AI status
Completed
Completed
100%
Causes
- Faulty steering angle sensor (internal failure)
- Damaged, corroded, or loose connector at the SAS
- Open, shorted or intermittent wiring in the SAS harness (including pinched/chafed wires in the steering column)
- Poor sensor power or ground
- Clock spring (spiral cable) damage affecting signal conductors
- CAN/LIN communication problems or module fault
Symptoms
- ABS, ESC, or traction control warning light illuminated
- Steering angle reading incorrect or shows no movement on scan tool
- Loss or reduction of electronic stability control and traction control functions
- Cruise control or lane-keeping assist degraded or disabled
- Intermittent faults that may clear and return
- Possible engine/driveability warnings if system shares sensors
What to check
- Use a scan tool to read DTCs and freeze-frame data; note vehicle speed, VOC, and whether code is current or intermittent
- Check live data for steering angle sensor values while turning the wheel — values should change smoothly and correspond with steering wheel motion
- Visual inspection of SAS connector and wiring for damage, corrosion, or loose terminals
- Check steering column, clockspring, and related harness routing for chafing where wiring moves
- Verify battery voltage and chassis/control module grounds are good
- Perform a wiggle test of the harness while observing live data for intermittent changes
Signal parameters
- Sensor reference voltage typically 5 V ±10% (verify against vehicle spec)
- Ground near 0 V with good continuity to chassis ground
- Output channels commonly between ~0.5–4.5 V (analog Hall/sine-cosine) and should vary smoothly with wheel rotation
- Digital/encoder sensors may output incremental pulses or CAN messages — verify regular message rate on bus with scan tool or scope
- No sudden jumps, dropouts, or fixed values when steering wheel is moved
Diagnostic algorithm
- Safety: Park vehicle on level surface, chock wheels, and disconnect battery if required by manufacturer before connectors/clock spring work.
- Read and record stored DTCs, freeze frame and live steering angle data using a capable scan tool.
- Visually inspect SAS connector, pins, and harness through full range of steering column travel for chafing or loose terminals; repair any damage.
- With ignition ON (engine may be off per service manual), backprobe SAS connector: verify reference voltage, sensor ground continuity, and that output channels change when turning the wheel. Use oscilloscope for better waveform analysis if available.
- Perform wiggle test on harness and connector while monitoring live data for intermittent faults. Repair/replace wiring if intermittent behavior occurs.
- Check clock spring for open circuits or damage; replace if pathways are broken or pins are damaged.
- Inspect related module grounds and power supplies; repair poor ground or low supply voltage issues.
- If wiring and power/ground are good but sensor outputs are out of range or not changing, replace the steering angle sensor per service procedure.
- After repair or replacement, perform required SAS learn/calibration or steering angle reset with scan tool and confirm proper operation through test drive.
- Clear codes and re-scan after test drive; if code returns, escalate to module communications or control module diagnostics.
Likely causes
- Wiring harness chafed in the steering column causing intermittent contact
- Connector corrosion or bent pins at the SAS
- Failed SAS module (common with age or water ingress)
- Clock spring worn or damaged causing circuit breaks
- Loss of 5 V reference or ground from the control module
Fault status
Status
Steering Angle Sensor Circuit Malfunction — steering angle information unreliable. Stability/traction control may be limited. Inspect sensor, wiring, and perform SAS calibration.
Repair difficulty: Medium
Diagnostic time: 0.5-2.5 hours
Similar codes
Repair manuals
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Code
C0240
OPEL
C — Chassis
Invalid Data from ECM (Engine Control Module)
Views:
UK: 21
EN: 31
RU: 20
AI status
Completed
Completed
100%
Causes
- Faulty steering angle sensor (internal failure)
- Damaged, corroded, or loose connector at the SAS
- Open, shorted or intermittent wiring in the SAS harness (including pinched/chafed wires in the steering column)
- Poor sensor power or ground
- Clock spring (spiral cable) damage affecting signal conductors
- CAN/LIN communication problems or module fault
Symptoms
- ABS, ESC, or traction control warning light illuminated
- Steering angle reading incorrect or shows no movement on scan tool
- Loss or reduction of electronic stability control and traction control functions
- Cruise control or lane-keeping assist degraded or disabled
- Intermittent faults that may clear and return
- Possible engine/driveability warnings if system shares sensors
What to check
- Use a scan tool to read DTCs and freeze-frame data; note vehicle speed, VOC, and whether code is current or intermittent
- Check live data for steering angle sensor values while turning the wheel — values should change smoothly and correspond with steering wheel motion
- Visual inspection of SAS connector and wiring for damage, corrosion, or loose terminals
- Check steering column, clockspring, and related harness routing for chafing where wiring moves
- Verify battery voltage and chassis/control module grounds are good
- Perform a wiggle test of the harness while observing live data for intermittent changes
Signal parameters
- Sensor reference voltage typically 5 V ±10% (verify against vehicle spec)
- Ground near 0 V with good continuity to chassis ground
- Output channels commonly between ~0.5–4.5 V (analog Hall/sine-cosine) and should vary smoothly with wheel rotation
- Digital/encoder sensors may output incremental pulses or CAN messages — verify regular message rate on bus with scan tool or scope
- No sudden jumps, dropouts, or fixed values when steering wheel is moved
Diagnostic algorithm
- Safety: Park vehicle on level surface, chock wheels, and disconnect battery if required by manufacturer before connectors/clock spring work.
- Read and record stored DTCs, freeze frame and live steering angle data using a capable scan tool.
- Visually inspect SAS connector, pins, and harness through full range of steering column travel for chafing or loose terminals; repair any damage.
- With ignition ON (engine may be off per service manual), backprobe SAS connector: verify reference voltage, sensor ground continuity, and that output channels change when turning the wheel. Use oscilloscope for better waveform analysis if available.
- Perform wiggle test on harness and connector while monitoring live data for intermittent faults. Repair/replace wiring if intermittent behavior occurs.
- Check clock spring for open circuits or damage; replace if pathways are broken or pins are damaged.
- Inspect related module grounds and power supplies; repair poor ground or low supply voltage issues.
- If wiring and power/ground are good but sensor outputs are out of range or not changing, replace the steering angle sensor per service procedure.
- After repair or replacement, perform required SAS learn/calibration or steering angle reset with scan tool and confirm proper operation through test drive.
- Clear codes and re-scan after test drive; if code returns, escalate to module communications or control module diagnostics.
Likely causes
- Wiring harness chafed in the steering column causing intermittent contact
- Connector corrosion or bent pins at the SAS
- Failed SAS module (common with age or water ingress)
- Clock spring worn or damaged causing circuit breaks
- Loss of 5 V reference or ground from the control module
Fault status
Status
Steering Angle Sensor Circuit Malfunction — steering angle information unreliable. Stability/traction control may be limited. Inspect sensor, wiring, and perform SAS calibration.
Repair difficulty: Medium
Diagnostic time: 0.5-2.5 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email