P0712 on 2016-2022 Honda HR-V: CVT Temperature Sensor Circuit Low Causes and Fixes

What's Unique About the 2016-2022 Honda HR-V

For the 2016-2022 HR-V with its second-generation Continuously Variable Transmission (CVT), the fluid temperature sensor is not a simple, separate part. It is integrated into the internal transmission wire harness (sometimes called the solenoid harness) located inside the transmission oil pan. This design means that a sensor failure often requires the replacement of the entire internal harness assembly, making the repair more complex than on vehicles with an external, screw-in sensor. This generation of HR-V also has known CVT durability concerns, leading Honda to issue a software update (TSB 21-046) and a warranty extension (TSB 21-047) for potential CVT belt failure, highlighting the sensitivity of this transmission.

Generation note: The 2016-2022 year range in North America covers the second generation (model code RU) of the Honda HR-V. The third generation began with the 2023 model year, so this guide is specific to the second generation.

Symptoms You May Notice

• Check Engine Light is on
• Blinking 'D' (Drive) indicator on the instrument cluster
🎬 See why your D light is flashing and how to fix it.
• Harsh, erratic, or delayed shifting
• Vehicle may enter 'limp mode' with significantly reduced power
• Transmission may not shift at all
• Possible transmission overheating warning light, even if the fluid isn't hot
• Improper torque converter clutch operation

Most Likely Causes

1. Failed Internal Transmission Wire Harness (with integrated Temperature Sensor) 🔴 High Probability → Shop Transmission Assembly On this CVT, the sensor is part of an internal harness that lives in hot transmission fluid, leading to degradation and electrical shorts over time. This is the most common point of failure for this specific code.
   How to confirm: After confirming the short is not in the external wiring (see next cause), the fault is confirmed to be internal. A technician will disconnect the main transmission harness connector and check the sensor voltage; if it remains low, the short is external, but if the voltage goes high (open circuit), the short is internal to the transmission.
   Typical fix: Drop the transmission oil pan and replace the entire internal wire harness assembly. 🎬 Watch: Step-by-step guide to replacing the internal CVT harness. This also requires refilling with approximately 4-5 quarts of the correct Honda HCF-2 CVT fluid.
   Est. part cost: $150-$250
2. Shorted External Wiring Harness 🟡 Medium Probability Wires can chafe against the chassis or other components, or connectors can become contaminated with moisture and corrode, leading to a short to ground in the sensor's signal circuit.
   How to confirm: Disconnect the main harness connector at the transmission. Use a multimeter to check for continuity to ground on the temperature sensor signal wire running back to the PCM. If continuity is found, the external harness is shorted.
   Typical fix: Locate the short in the wiring harness and repair the damaged section. Replace corroded connectors if necessary.
   Est. part cost: $10-$50

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): → Shop Engine Control Module (ECM) This is the least likely cause. The PCM should only be suspected if both the internal and external wiring and the sensor itself have been tested and confirmed to be in good working order.

Diagnosis Steps

1. Connect a professional OBD-II scanner (preferably a Honda HDS) to the vehicle.
2. View the live data stream for the 'CVT Fluid Temperature' or 'TFT Sensor'.
3. Confirm the reading is an illogically low value (e.g., -40°F) or that the sensor voltage is below the manufacturer's threshold (typically <0.07V).
4. Perform a visual inspection of the external transmission wiring harness and its connectors for any signs of damage, corrosion, or loose pins.
5. Disconnect the main electrical connector (the 8P connector) at the transmission case.
6. Re-check the sensor voltage on the scan tool. If the voltage now reads high (indicating an open circuit), the short is located inside the transmission, pointing to a faulty internal harness/sensor.
7. If the voltage remains low after disconnecting the harness, the short circuit is in the wiring between the connector and the PCM, or in the PCM itself.
8. If the fault is internal, the transmission oil pan must be removed to access and replace the internal wire harness assembly.
9. After the repair, refill the transmission with genuine Honda HCF-2 fluid, clear the code, and perform a test drive to ensure the transmission operates correctly and the code does not return.

Parts You'll Likely Need

• Internal Transmission Wire Harness / Solenoid Harness (OEM #28240-59B-000) — This is the most common failure point for a P0712 code on this vehicle, as the CVT fluid temperature sensor is integrated into this harness which fails from heat and fluid exposure.
  Trusted brands: Honda (Genuine OEM)
  OEM price range: $150-$250
  Aftermarket price range: $100-$180
• Honda HCF-2 CVT Fluid (OEM #08200-HCF2) — Required to refill the transmission after dropping the pan to replace the internal harness. Using the correct fluid is critical for CVT longevity.
  Trusted brands: Honda (Genuine OEM)
  OEM price range: $15-$25 per quart
• Transmission Pan Gasket — Should be replaced when the transmission pan is removed to prevent leaks.
  Trusted brands: Honda (Genuine OEM), Fel-Pro, Mahle
  OEM price range: $20-$40
  Aftermarket price range: $15-$30

Technical Service Bulletins (TSBs) & Recalls

• 21-046 - Product Update: 2016-20 HR-V Software Update and CVT Inspection
• 21-047 - Warranty Extension: 2016-20 HR-V CVT Premature Belt Deterioration

Platform-Specific Known Issues

• Honda Service Bulletin 21-046 addresses a software update for the PCM to improve CVT durability and prevent belt damage. An incorrect software value could cause excessive pressure on the belt, leading to breakage. This update helps revise operational loads and adds DTC P271E to detect early belt failure.
• Honda extended the warranty on the CVT for 2016-2020 models to 7 years or 150,000 miles due to potential premature belt deterioration (Service Bulletin 21-047). This highlights the importance of correctly functioning transmission sensors for the longevity of the unit.

Mechanic-Grade Diagnostic Values

• CVT Fluid Temperature Sensor Voltage (Live Data) — expected: Varies with temperature, but should be well above 0.07V.. Failure: A voltage reading of less than 0.07V indicates a short circuit.
• CVT Fluid Temperature Sensor Resistance — expected: Approximately 2.0-2.5 kOhms at 20°C (68°F). Resistance decreases as temperature increases.. Failure: A reading near zero ohms indicates an internally shorted sensor.
• Sensor Reference Voltage at Harness Connector — expected: Approximately 5.0V with key on, engine off.. Failure: A voltage significantly below 5.0V indicates a problem with the PCM or the wiring providing the reference signal.
• PCM Ground Circuit Voltage Drop — expected: Less than 0.1V (100mV).. Failure: A reading above 0.1V between the sensor's ground pin at the connector and the negative battery terminal indicates excessive resistance in the ground circuit.

Scan Tool Commands That Help

• Honda Diagnostic System (HDS): Jump SCS (Service Check Connector) line — This function is used to set up a specific diagnostic environment before performing continuity checks on the PCM connector pins, as part of the official troubleshooting procedure for an external wiring short.
• Professional Scan Tool (e.g., Honda HDS, Autel, Snap-on): Reset Transmission Adaptation Values — After replacing the internal harness or other major transmission components, resetting the learned shift adaptations is recommended to ensure the transmission operates smoothly with the new parts.

Wiring & Ground Locations

• G101 — Main engine ground, typically located on the engine block or thermostat housing area, at the left rear of the engine compartment.. A poor G101 ground can cause numerous electrical issues, including incorrect sensor readings. It serves as the power and logic ground for the ECU.
• PCM Connector B (51P), Pin B9 — This is a specific pin on the 51-pin connector (Connector B) at the Powertrain Control Module (PCM), which is located on the left side of the engine compartment.. This is the specific pin for the CVT fluid temperature sensor signal (TATF line) that must be tested for continuity to ground when diagnosing an external wiring short.
• Transmission Main Connector (8P) — This is the 8-pin main electrical connector on the transmission case that connects the internal harness to the engine wiring harness.. This is the primary disconnection point for isolating the fault between the internal transmission components and the external vehicle wiring.

Model Year Variations Within This Range

• 2019-2022: The 2019 model year introduced a facelift with new Sport and Touring trims. While the core 1.8L engine and CVT remained, Honda noted the CVT was recalibrated to 'maintain lower rpm' and provide more engine braking on deceleration, indicating software changes.
• 2016-2018: These earlier models were available with a 6-speed manual transmission option, which was discontinued for the 2019 facelift. The P0712 code only applies to CVT models.
• 2020-2022: The Honda Sensing suite of safety features became standard equipment on all trims starting in the 2020 model year.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• CVT Premature Belt Deterioration 🔴 High — Common enough for Honda to issue a warranty extension to 7 years/150,000 miles for 2016-2020 models. (Ref: TSB 21-046, TSB 21-047)
• Starter Motor / Push-to-Start Button Failure 🟠 Medium — Numerous owner complaints of intermittent no-start conditions, where the starter doesn't engage on the first press. (Ref: TSB 20-116 (Warranty extension for start/stop switch))
• Peeling White Paint 🟡 Low — Affects specific white paint colors (e.g., White Orchid Pearl) on 2016-2018 models, leading to flaking and peeling. (Ref: TSB 19-057 (Warranty extension for paint))
• Fuel Pump Failure 🔴 High — A recall was issued for certain 2018-2020 models due to a fuel pump that may fail, causing the engine to stall. (Ref: NHTSA Recall 20V-314)
• Rear-View Camera Failure 🟡 Low — A recall was issued for 2019-2022 models where the rearview camera image may not display when starting the vehicle. (Ref: NHTSA Recall 23V-046)

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For this specific repair, using a used part is strongly discouraged for the primary failure component. A used Powertrain Control Module (PCM) could be considered as a last resort if the original is confirmed faulty, but it must be an exact part number match and will require professional programming.

Donor-vehicle mileage cap: roughly under 1 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• For a used PCM: Ensure the part number on the label is an exact match to the original. Inspect the connectors for any bent, corroded, or pushed-out pins. Avoid any units with signs of water damage or physical case damage.
• For a used internal harness (NOT RECOMMENDED): Check for brittle or stiff wiring, cracks in the plastic connectors, and any signs of corrosion on the pins. The risk of premature failure remains extremely high regardless of visual condition.

OEM-only on this vehicle (don't cheap out):

• Internal Transmission Wire Harness: This is the most common failure part. Given the labor involved in accessing it, using a new Genuine Honda OEM part is critical to ensure longevity and avoid a repeat repair.
• Honda HCF-2 CVT Fluid: This transmission is highly sensitive to fluid type. Using only the specified HCF-2 fluid is essential for proper operation and to prevent long-term damage.

Brands owners have reported issues with on this vehicle:

• Generic/unbranded internal wiring harnesses from online marketplaces. While cheap, their long-term durability when submerged in hot transmission fluid is questionable and they often have issues with pin fitment or wire quality.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• P0713 — Indicates a 'Circuit High' fault for the same Transmission Fluid Temperature Sensor. P0712 (Circuit Low) and P0713 (Circuit High) are companion codes that point to an issue with the same sensor or its wiring, just with opposite electrical failure modes (short vs. open).
• P177C — Reported by an owner on hrvforum.com as appearing simultaneously with P0712. This suggests it may be a secondary code triggered by the invalid temperature data or a related fault in the CVT's electronic control system.
• P271E — A diagnostic trouble code added by Honda via a software update (TSB 21-046) to detect early CVT belt failure. An incorrect temperature reading from a faulty sensor (causing P0712) can lead to improper line pressure control, increasing stress on the CVT belt and potentially triggering this code.
• P0741 — This code relates to the Torque Converter Clutch (TCC) solenoid circuit. The PCM uses fluid temperature as a key input for TCC operation. An invalid temperature signal from a P0712 fault can cause improper TCC engagement or disengagement, leading to this secondary code.

Frequently Asked Questions