C1A37

Code

Generic C — Chassis

EPS Torque Sensor Circuit Intermittent

Brand: Generic

Type: C — Chassis

Views: UK: 14 EN: 53 RU: 15

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Page language: EN

Causes

Loose, corroded or damaged connector(s) at the torque sensor or EPS control module
Broken, chafed or intermittent wiring between the torque sensor and EPS module
Poor sensor ground or supply voltage (voltage drop, bad splice, weak battery)
Intermittent internal fault in the torque sensor
Intermittent fault in EPS control module or module power/ground
Water ingress or contamination at connectors or in the steering column

Symptoms

EPS warning lamp or master warning lamp illuminated
Intermittent loss or reduction of power steering assist
Steering feels erratic, heavy, or inconsistent under certain conditions
May set additional EPS-related codes or enter limp/backup steering mode
Code may clear and return unpredictably or only under specific steering/wheel positions

What to check

Scan for stored/freeze-frame codes and note occurrence conditions (vehicle speed, steering angle, temperature)
Check battery voltage and charging system health
Visually inspect torque sensor connector(s) and wiring for damage, corrosion, or water entry
With ignition ON, backprobe sensor supply and ground for correct voltages
Use live data to monitor torque sensor output values while turning the steering wheel
Wiggle-test wiring and connector while monitoring live data and codes to try to reproduce the intermittent

Signal parameters

Sensor supply voltage typically 5 V reference (verify vehicle-specific value) — should be stable within ±0.1–0.2 V
Signal output(s) often a differential pair or single-ended around a reference (commonly ≈2.5 V center) — should change smoothly with steering torque
Expected signal range typically ~0.5–4.5 V (vehicle-specific); sudden spikes, drops to 0 V, or open circuit indicate a fault
Signal update rate depends on vehicle (tens to hundreds of Hz) — look for missing samples or irregular timing
Ground continuity to chassis and module ground should be near 0 Ω; high resistance may cause intermittent readings

Diagnostic algorithm

Retrieve all stored and pending codes; record freeze-frame and live data where code set.
Inspect connectors and wiring at the torque sensor and EPS control module for corrosion, pin damage, or water intrusion. Repair any visible issues.
Check battery and charging system; ensure stable supply voltage during cranking and driving.
With a scan tool, monitor torque sensor raw voltages, torque/driver torque values and related parameters while turning the wheel slowly and while driving. Note any dropouts or implausible jumps.
Backprobe the sensor connector: verify supply, reference, signal and ground voltages with ignition ON. Compare to vehicle specifications.
Wiggle test the steering column harness and connectors while watching live data and codes to try to reproduce the intermittent condition. If code appears with a specific harness position, repair wiring or connector.
Use an oscilloscope to capture signal(s) during normal operation and while manipulating wiring/connector to detect intermittent opens, shorts, noise or missing pulses.
If wiring and connectors test OK, swap or bench-test the torque sensor if possible, or substitute a known-good sensor per service procedures.
If sensor replacement is performed, follow any required calibration or steering angle/torque sensor relearn procedures.
Clear codes and road-test vehicle under the conditions that previously caused the fault to confirm repair. If intermittent persists, escalate to module bench test or manufacturer diagnostics.

Likely causes

Damaged wiring/harness in steering column (most common)
Corroded or loose connector pins at torque sensor
Intermittent sensor internal failure

Fault status

⚠️ Status

Intermittent fault detected in EPS torque sensor circuit — signal dropouts or irregular readings observed between torque sensor and EPS control module.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5-3.0 hours