OBD-II Code
P1690
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$80–$700
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
$80 (transponder key DIY) to $700 (SMARTRA module + dealer coding).
P1690 on Hyundai/Kia is Immobilizer Lamp Circuit Malfunction — the body control module or engine ECU couldn't communicate with the immobilizer/transponder system, the dash lamp circuit shorted, or the transceiver coil around the ignition lock cylinder failed.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureP1690 on Hyundai/Kia is Immobilizer Lamp Circuit Malfunction — the body control module or engine ECU couldn't communicate with the immobilizer/transp…
P1690 on Hyundai/Kia is Immobilizer Lamp Circuit Malfunction — the body control module or engine ECU couldn't communicate with the immobilizer/transponder system, the dash lamp circuit shorted, or the transceiver coil around the ignition lock cylinder failed.
This is an anti-theft fault
the car may start once and stall after 2-3 seconds (Hyundai's anti-theft startup-and-die behavior), or fail to crank at all. Cheapest-first ladder: scan with a scan tool that can talk to the SMARTRA/immobilizer module (cheap generic OBD scanners often can't read these) and check for related codes like B1670/B2799 alongside P1690. Try a known-good spare key — if the spare starts the car cleanly, the original key's transponder chip is dead and needs to be re-coded or replaced. Measure the transceiver coil (the ring antenna around the ignition cylinder) for continuity — typical spec is 1-3 ohms; an open coil means a new antenna ring. Inspect the dash immobilizer lamp circuit for a shorted bulb or LED driver. Don't go straight to ECM/SMARTRA replacement — these modules are $400-$900 and have to be coded to the VIN by a dealer or capable locksmith; the fault is usually a $30 transponder chip or a $80 antenna ring.
Vehicle-specific patterns2007-2012 Hyundai Elantra / Kia Forte with the Nu 2.0L is one of the most common P1690 platforms — the antenna ring inside the steering column fails…
- 2007-2012Hyundai Elantra / Kia Forte with the Nu 2.0L is one of the most common P1690 platforms — the antenna ring inside the steering column fails from heat and vibration.
- 2006-2010Sonata 2.4L Theta and 2011-2015 Sonata Theta II both throw P1690 from SMARTRA module failure after long-term battery drain events (a dead battery left for weeks can corrupt the SMARTRA pairing).
- 2010-2014Kia Soul / Hyundai Accent / Kia Rio show P1690 from transponder chip failure in the key itself — common when the key has been dropped on a hard surface repeatedly.
- 2014+ vehicles with proximity smart-key (push-button start) throw P1690 less often, but when they do, the fix involves the smart-key control unit, not the column antenna.
Estimated repair$80 (transponder key DIY) to $700 (SMARTRA module + dealer coding).
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