C168300

Code

HYUNDAI C — Chassis

Signal Driver Buckled Input State not Valid

Brand: HYUNDAI

Type: C — Chassis

Views: UK: 15 EN: 17 RU: 18

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Faulty or intermittent driver seat belt buckle switch (mechanical or electrical failure)
Damaged wiring harness, broken wire, short to battery/ground, or corrosion at connector
Poor or corroded connector pins at the buckle, seat wiring harness, or RCM/SDM
Incorrect reference/pull‑up voltage from the control module or blown fuse
Aftermarket equipment or previous repairs that disturbed wiring or connectors
Faulty restraint control module (rare) or software anomaly

Symptoms

DTC C168300 stored in the airbag / restraint system module memory
SRS/airbag warning lamp illuminated on instrument cluster
Seat belt reminder lamp/chime may behave incorrectly (may not register buckled/unbuckled)
Possible intermittent or no change in seat belt indicator when buckle is operated

What to check

Read and record freeze frame and any related DTCs with a capable scan tool (airbag/RCM data)
Visually inspect driver seat buckle connector and wiring for damage, corrosion, or loose pins
Operate the buckle while monitoring live data for the buckle input on the scan tool (open/close states)
Check related fuses and power/ground circuits for the restraint control module
Perform a wiggle test of the seat harness while observing live input for intermittent changes
Compare buckle input behavior to passenger side or spec values if available

Signal parameters

Type: normally open/closed switch (discrete digital input) — reports two states
Expected resistance: closed (buckled) ≈ 0–5 Ω; open (unbuckled) ≈ very high (kΩ to open). Exact values vary by model.
Expected voltage: with module pull‑up, open may show pull‑up voltage (≈5 V) and closed pulled to ground (≈0 V). Some systems use battery voltage levels—refer to service manual.
Signal changes should be stable and debounced when buckle is operated (no rapid toggling)
No unexpected intermediate voltages between open and closed

Diagnostic algorithm

Retrieve DTC(s) and freeze frame with a diagnostic scanner capable of reading the vehicle's RCM/airbag module. Note any related codes.
Verify SRS lamp condition and confirm C168300 is current. Do not deploy airbag or perform servicing on airbag components without following safety procedures.
Visually inspect the driver seat buckle assembly, connector, and seat wiring for damage, corrosion, or loose pins. Repair as required.
With ignition ON (follow manufacturer safety procedures), monitor the buckle input on the scan tool while operating the buckle. Confirm the input changes cleanly between two states.
If input is intermittent or stuck, disconnect the buckle switch connector and measure resistance across the switch while operating the latch. Expect near‑0 Ω when closed, open/infinite when open. If readings are incorrect, replace the buckle switch.
If switch tests good, inspect and backprobe the connector at the harness/RCM for reference voltage/pull‑up and ground. Verify continuity to the module and proper reference voltage (typically ~5 V or battery depending on design).
Perform a continuity/short check from the buckle connector to the module to locate opens or shorts to battery/ground. Repair wiring harness as needed (splice or replace harness section).
After repairs, clear codes and retest operation through several buckle cycles and road ignition cycles to confirm code does not return.
If wiring and switch test good and code persists, consider module input circuitry fault—verify software level and consult manufacturer technical service info before replacing the RCM/SDM.
Always perform an SRS system check and follow safety/repair procedures in the factory service manual when handling seat belt buckle, inflator, or module components.

Likely causes

Contaminated/corroded connector at driver buckle (high likelihood)
Broken/frayed wire in the seat harness due to seat movement
Failed buckle switch contacts (sticking or intermittent)
Poor ground or open reference/pull‑up inside module or wiring

Fault status

⚠️ Status

Driver seat belt buckle input state invalid — buckle switch signal out of expected range or intermittent.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 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