C1705 Infiniti Q50 Trouble Code: Right Front TPMS Causes and Fixes (2016-2020)

What's Unique About the 2016-2020 Infiniti Q50

On the Infiniti Q50, this code is strongly associated with very slow air leaks from the tire. Infiniti issued a specific Technical Service Bulletin (ITB20-003) to address this, noting that a pressure loss of as little as 1 psi every few days can trigger the C1705 code. The bulletin points to a potential leak between the TPMS sensor's valve stem and the valve nut, which can often be fixed by replacing a small seal and nut rather than the entire sensor assembly. The 2016-2020 Q50 models use a 433 MHz frequency sensor, which is different from the 315 MHz sensors used in 2014-2015 models.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Solid TPMS warning light on the dashboard.
• Vehicle information display shows a low tire pressure warning for the right front tire.
• A TPMS light that flashes for about one minute upon startup and then stays solid, indicating a sensor or system fault.

Most Likely Causes

1. Slow Tire Leak from Valve Stem Seal 🔴 High Probability Infiniti TSB ITB20-003 was issued specifically for this problem on 2014-2020 Q50 and 2017-2020 Q60 models. It's a known failure point of the seal.
   How to confirm: Inflate the tire to the correct pressure noted on the driver's door jamb sticker (typically around 35 psi for this test). Spray the valve stem area with soapy water and look for bubbles, which indicate a leak.
   Typical fix: If the leak is at the valve stem, the TSB procedure is to replace the valve stem washer/seal and valve nut, then torque the new nut to the specified 10 N·m (88.5 in-lb). This can be done without replacing the entire sensor.
   Est. part cost: $5-$20 for a TPMS service kit.
2. Failing TPMS Sensor 🔴 High Probability The internal batteries in TPMS sensors have a finite lifespan, typically 5-10 years. Vehicles in the 2016-2020 range are now entering the age window where battery failures are common.
   How to confirm: A professional TPMS diagnostic tool can attempt to read the sensor's data. If the tool cannot communicate with the sensor or shows a low battery level, the sensor has likely failed. A flashing TPMS light is a strong indicator 🎬 Watch: A walkthrough on resolving the C1705 sensor code of sensor failure.
   Typical fix: Replace the right front TPMS sensor. The new sensor must be the correct frequency (433 MHz for 2016+ models) and must be programmed to the vehicle using a TPMS tool.
   Est. part cost: $70-$135 for an OEM sensor, $40-$80 for a quality aftermarket sensor.
3. Low Tire Pressure 🟡 Medium Probability
   How to confirm: Check the pressure of the right front tire with a reliable tire pressure gauge. Compare it to the recommended pressure on the door jamb sticker.
   Typical fix: Inflate the tire to the correct pressure. The light should go off after driving for several minutes at speeds above 16-25 mph. 🎬 See this quick guide on resetting the flat tire warning
   Est. part cost: $0

Rare But Worth Checking

• Faulty Body Control Module (BCM):

Diagnosis Steps

1. Use a quality tire pressure gauge to check the pressure in all four tires. Inflate them to the specification listed on the driver's door jamb.
2. Carefully inspect the right front tire for any obvious punctures or damage.
3. Spray the TPMS valve stem on the right front wheel with soapy water. Look for bubbles forming around the base of the stem, which indicates a leak as described in TSB ITB20-003.
4. Drive the vehicle for at least 10-15 minutes at speeds over 25 mph to allow the system to reset. If the light returns, proceed to the next step.
5. Use a TPMS diagnostic tool to attempt to read the data from the right front sensor (ID, pressure, temperature, battery status). A flashing light on the dash is a strong indicator of a sensor/system fault.
6. If the tool cannot get a reading or reports a low battery, the sensor needs to be replaced. Ensure the replacement is a 433 MHz sensor.
7. If the sensor reads correctly but the pressure is dropping, a slow leak exists in the tire or wheel that must be found and repaired. The valve stem seal is the most likely culprit per the TSB.
8. If a new sensor is installed, use the TPMS tool to perform the relearn procedure to register the new sensor ID with the car's computer. This service typically costs between $49 and $72.
9. If a known-good sensor will not register with the BCM, investigate for wiring issues or a potential fault in the Body Control Module itself.

Parts You'll Likely Need

• Tire Pressure Monitoring System (TPMS) Sensor (OEM #40700-4GA0B (supersedes 40700-4GA0A)) — This is the direct cause of the code if the sensor's battery has died or it has failed internally. For 2016+ models, it must be 433 MHz.
  Trusted brands: Infiniti (OEM), Schrader, Autel, Continental
  OEM price range: $100-$140
  Aftermarket price range: $40-$80
• TPMS Sensor Service Kit (OEM #40780-JA01B (example part, verify for specific sensor)) — If the sensor itself is good but leaking from the valve stem, replacing the seal and nut from a service kit can fix the issue per TSB ITB20-003.
  Trusted brands: Dorman, Schrader, Hamaton
  OEM price range: $10-$20
  Aftermarket price range: $5-$15

Related Codes That Often Appear With This One

• C1704 — This code corresponds to the Left Front TPMS sensor. It's common to see multiple TPMS codes if tires haven't been checked in a while or if multiple sensors are failing around the same time due to age.
• C1706 — This code corresponds to the Right Rear TPMS sensor. Seeing it with C1705 could indicate a widespread issue with tire pressures or sensor age.
• C1707 — This code corresponds to the Left Rear TPMS sensor. Like the others, its presence points to a potential systemic issue rather than an isolated one.

Technical Service Bulletins (TSBs) & Recalls

• ITB20-003 / NHTSA ID 10171783: Details a common cause for TPMS codes related to a slow air leak at the sensor's valve stem seal, and provides a specific repair procedure including a new torque specification. Applies to both Q50 and Q60.

Platform-Specific Known Issues

• Infiniti Technical Service Bulletin ITB20-003 describes a known issue where a slow air leak can occur between the TPMS sensor's valve stem and the valve nut, triggering codes C1704, C1705, C1706, or C1707. The fix involves replacing the valve stem washer/seal and retorquing the nut to a new specification of 10 N·m.
• Some owners report issues getting aftermarket TPMS sensors to be recognized by the vehicle's system, even after multiple relearn attempts by tire shops. This can sometimes necessitate a visit to an Infiniti dealer for programming with their proprietary CONSULT tool.

Mechanic-Grade Diagnostic Values

• TPMS Sensor Valve Nut Torque (per TSB ITB20-003) — expected: 10 N·m ±0.5 (88.5 in-lb). Failure: Incorrect torque can lead to leaks (too loose) or damage to the sensor/stem (too tight).
• TPMS Sensor Valve Nut Torque (Schrader OEM-supplier spec) — expected: 8 N·m (71 in-lbs). Failure: This is an alternative spec from a major OEM supplier; deviation can cause leaks.
• TPMS Valve Core Torque — expected: 0.4 N·m (3.5 in-lbs). Failure: An over-tightened core can be damaged, while a loose core will leak air.
• Tire Inflation Indicator Over-Inflation Warning — expected: Horn beeps once at correct pressure. If over-inflated by approx. 4 PSI, horn beeps again and hazard lights flash three times.. Failure: This feature helps confirm system operation; its absence may indicate a problem or use of non-compliant aftermarket sensors.

Scan Tool Commands That Help

• Infiniti CONSULT-III plus / Aftermarket (Autel, ATEQ): TPMS ID Registration / Position Relearn — This function is required after replacing a TPMS sensor to write the new sensor's unique ID to the Body Control Module (BCM), allowing the vehicle to recognize it.
• ECUTek (with Autel TPMS Pad): TPMS Registration — For owners of modified vehicles with an ECUTek tuning dongle, this provides a method to perform the TPMS relearn procedure through the ECUTek phone app, bypassing the need for a separate trip to a tire shop.

Wiring & Ground Locations

• Body Control Module (BCM) — Located on the passenger side of the vehicle, mounted vertically behind the right-side kick panel.. The BCM contains the TPMS receiver. All wireless signals from the tire sensors are sent to this module. Any diagnosis of a total system failure (all sensors not reading) or failed registration would require accessing the BCM and its connectors/grounds.

Real Owner Repair Stories

• Reddit user Ok_Focus_6784 (Infiniti Q50 (year not specified, but post-2016 implied by context)) — Needed to replace TPMS sensors after changing wheels.
  ❌ Tried (didn't work) N/A
  ✅ What actually fixed it The user installed aftermarket sensors from eBay which functioned for reading pressure, but they noted a loss of a specific OEM feature: the horn no longer honked to indicate the correct pressure had been reached while inflating the tires. This highlights a subtle incompatibility with some aftermarket parts.
• Reddit user Swagggles (EU-spec Infiniti Q50, built in 2015 but first registered in 2017.) — Needed new TPMS sensors.
  ❌ Tried (didn't work) N/A
  ✅ What actually fixed it The user successfully used 433MHz sensors. They noted that even though the car was built in 2015 (a year associated with 315MHz sensors in the US market), EU-spec cars used 433MHz because the 315MHz frequency is illegal there. This is a key detail for anyone with a non-US market vehicle.

OEM Part Supersession History

• 40700-4GA0A → 40700-4GA0B — Standard part revision by the manufacturer.
  Heads up: Part 40700-4GA0B is the 433 MHz sensor for 2016+ models. Some parts catalogs create confusion by listing it for models with a production date up to '12/2015'. The critical factor is ensuring the sensor frequency (433 MHz) matches the vehicle year (2016+), not just the part number lookup.

Model Year Variations Within This Range

• 2016-2020: These models use a 433 MHz TPMS sensor frequency, distinct from the 315 MHz frequency used on 2014-2015 models. Using the wrong frequency will result in a failed registration.
• 2016-2020: These models are equipped with a 'Tire Inflation Indicator' system, which honks the horn once the correct tire pressure is reached during inflation. Some owners report this feature ceases to function after installing aftermarket (non-OEM) TPMS sensors, even if the sensors report pressure correctly.