C1338

Code

HYUNDAI C — Chassis

Right Front LFI Pulse Fail Detect | Right Front Low Frequency Initiator Fail Pulse Detected

Brand: HYUNDAI

Type: C — Chassis

Views: UK: 23 EN: 30 RU: 21

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Page language: EN

Open or shorted wiring between the right front wheel speed sensor and ABS/ESC module
Corroded, loose, or damaged connector at the sensor or module
Failed right front wheel speed (LFI) sensor
Damaged or contaminated tone ring/reluctor (missing teeth, heavy rust, debris)
Faulty ABS/ESC control module or internal driver circuit
Aftermarket or repair work that disturbed sensor alignment or wiring

ABS and/or ESC/TRAC warning lamp illuminated
Possible loss of ABS, traction control, or stability control functionality
Brake feel often unchanged in normal driving, but ABS may not engage on that wheel
Diagnostic trouble codes related to wheel speed or ABS circuitry
Occasional intermittent warning if the fault is intermittent

Read freeze frame and live data with an OBD2/ABS scan tool to confirm right front wheel speed sensor output
Visual inspection of right front sensor, connector, and wiring harness for damage, corrosion, or pin push-out
Check tone ring (reluctor) condition for missing teeth, heavy rust, cracks, or debris
Backprobe sensor connector and measure resistance and signal while spinning the wheel (or using spin tool)
Perform voltage/continuity tests from sensor connector to ABS module; check for short to battery or ground
Wiggle test wiring while monitoring live data for intermittent changes

Sensor output: produces pulses proportional to wheel speed; frequency increases with wheel speed
Hall-effect sensors: digital square wave; expected amplitude typically 0–5 V (refer to vehicle spec)
Variable-reluctance (VR) sensors: AC waveform amplitude increases with speed; expected mV/VR range varies by design
Resistance: stationary DC resistance of sensor coil (if VR) should be within manufacturer spec (check service manual)
No pulses, very low amplitude, or irregular pulse spacing are indicative of a fault

Retrieve codes and live wheel speed data with an ABS-capable scan tool. Confirm C1338 is active and note any related codes.
Visually inspect the right front sensor, tone ring, and harness for damage, contamination, or loose connectors. Repair obvious damage.
With ignition ON (engine off), backprobe the sensor connector and check for proper reference power and ground (if Hall sensor).
Measure sensor resistance (if applicable) and compare to spec. If resistance open or out of range, replace sensor.
Spin the wheel while monitoring live data or use an oscilloscope to confirm pulse waveform and frequency. No waveform or intermittent pulses indicate sensor/wiring/tone ring issues.
Check continuity between the sensor connector and the ABS module connector pins. Look for open circuits or high resistance. Also check for short to battery/ground.
Wiggle the wiring and connectors while monitoring data to find intermittent faults. Repair or replace damaged sections or connectors.
If wiring and sensor test good, swap with a known-good identical sensor (if available) to isolate sensor vs module.
If swapped sensor works, replace the faulty sensor and clear codes. If problem follows to module and all wiring checks are good, consider ABS module diagnosis/repair by a specialist.
After repair, clear codes and perform road test or wheel spin test to verify proper pulse and that the code does not return.

⚠️ Status

Right Front LFI pulse not detected — right front wheel speed signal missing or invalid. ABS/ESC may disable control for that wheel.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2 hours

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