P0712 on 2016-2022 Honda Pilot: Transmission Temp Sensor Circuit Low Causes and Fixes

What's Unique About the 2016-2022 Honda Pilot

The 2016-2022 Honda Pilot is unique because it was offered with two different automatic transmissions, and the fix depends on which one your vehicle has. Lower trims (LX, EX, EX-L) typically have a Honda-built 6-speed automatic (6AT), while higher trims (Touring, Elite) have a 9-speed automatic (9AT) made by ZF. While the code's meaning is the same for both, the specific temperature sensor part and its accessibility can differ. The 9-speed, in particular, had a number of software updates and owner complaints about shift quality early in its life cycle, as well as a warranty extension for a faulty ATF warmer that could cause coolant and ATF to mix (TSB 17-035).

Symptoms You May Notice

• Check Engine Light is on
• Flashing 'D' (Drive) indicator light on the dashboard
• Harsh, erratic, or delayed gear shifts
• Transmission may get stuck in one gear (limp mode)
• Reduced fuel economy
• Transmission temperature warning light may be illuminated
• Improper torque converter clutch operation

Most Likely Causes

1. Failed Internal Transmission Fluid Temperature (TFT) Sensor 🔴 High Probability → Shop Transmission Assembly The sensor is a thermistor that can fail internally, creating a short circuit that sends a constant low voltage signal to the PCM. This is the most common point of failure for this code.
   How to confirm: Using a scan tool, observe the live data for the TFT sensor. If it reads an illogical, fixed low temperature (like -40°F) even when the engine is warm, the sensor has likely failed. 🎬 Watch: Diagnostic walkthrough for P0712 on a Honda Pilot A technician can also test the sensor's resistance directly at the transmission connector pins.
   Typical fix: Replace the transmission fluid temperature sensor. This requires draining the transmission fluid, removing the transmission pan, and accessing the sensor, which is often attached to the valve body or internal harness.
   Est. part cost: $40-$100
2. Damaged Wiring or Connector 🟡 Medium Probability The wiring harness leading to the transmission can be damaged by road debris, heat, or improper repairs, causing a short to ground. Pins in the connector can also corrode, creating a voltage drop.
   How to confirm: Visually inspect the wiring harness running to the transmission for any signs of chafing, melting, or corrosion. A technician will perform a continuity test to check for a short to ground between the sensor connector and the PCM.
   Typical fix: Repair the damaged section of the wire or replace the faulty connector. In severe cases, a portion of the wiring harness may need to be replaced.
   Est. part cost: $10-$200

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): → Shop Engine Control Module (ECM) This is extremely rare. The PCM's internal circuit for reading the sensor could fail, but all other potential causes, especially the sensor and wiring, should be exhaustively ruled out before considering PCM replacement.

Diagnosis Steps

1. Connect a professional OBD-II scan tool to the vehicle.
2. Read the fault codes and confirm P0712 is present. Check for any other related transmission codes.
3. View the live data stream for the Transmission Fluid Temperature Sensor 'A'. A P0712 code will typically show a very low, static temperature reading (e.g., -40°F) or a voltage below 0.07V.
4. Inspect the transmission fluid level and condition. While not a direct cause, it's good practice.
5. Visually inspect the external transmission wiring harness and connectors for any obvious signs of damage, corrosion, or loose connections.
6. If wiring appears okay, the next step is to test the sensor circuit. This involves disconnecting the sensor (if accessible) and checking for voltage changes, or testing for continuity to ground on the signal wire between the PCM and the sensor connector.
7. If the wiring is confirmed to be good, the TFT sensor itself is faulty and must be replaced.

Parts You'll Likely Need

• Automatic Transmission Fluid Temperature Sensor (For 6-Speed) (OEM #28650-RWE-003) — This is the most common failure point for this code on the Honda-built 6-speed transmission. It fails internally, causing a short circuit.
  Trusted brands: Honda (Genuine), Carquest Premium, Duralast
  OEM price range: $60-$90
  Aftermarket price range: $40-$60
• Transmission Fluid Temperature Sensor (For 9-Speed) (OEM #28650-RT4-003) — For the ZF 9-speed transmission, the sensor is also a common failure point. Part number 28650-RT4-003 is listed for this application, though some sources note it may be part of a larger assembly or located in the AWD differential on some models. Professional diagnosis is required to confirm the exact part needed.
  Trusted brands: ZF (OEM), Honda (Genuine), Mopar (for other vehicles using the same transmission)
  OEM price range: $100-$250+
  Aftermarket price range: Varies
• Honda Genuine ATF DW-1 (For 6-Speed) or ATF Type 3.1 (For 9-Speed) — The transmission fluid must be drained to perform the repair and refilled with the correct OEM-specific fluid to ensure proper transmission function. 🎬 Watch: How to change ATF on 6-speed LX and EX trims
  Trusted brands: Honda (Genuine)
  OEM price range: $12-$20 per quart
  Aftermarket price range: N/A

Related Codes That Often Appear With This One

• P0713 — This is the opposite code, 'Circuit High,' indicating an open circuit. Seeing them together or intermittently could point to a loose connection or a failing sensor that is fluctuating between states.
• P0711 — This code means 'Circuit Range/Performance,' indicating the sensor's readings are erratic or illogical. It's another sign that the sensor itself or its wiring is failing.

Technical Service Bulletins (TSBs) & Recalls

• A23073 (NHTSA ID 10242219) - Service Bulletin for 2016-2020 Pilot: 'Transmission Temp Too Hot' message on the MID with no DTCs.
• 17-035 (NHTSA ID 10117329) - Warranty Extension for 2016-2017 Pilot with 9-speed A/T: Addresses defective ATF warmer causing poor shift quality or overheating.

Platform-Specific Known Issues

• Be aware of Honda Service Bulletin 23-073 for 2016-2020 Pilots. It addresses a 'Transmission Temperature Too Hot' message appearing *without* a DTC, caused by fluid foaming. The fix is a PCM software update and a triple ATF flush. While it doesn't cause P0712, it's a related temperature issue for this platform.
• For 9-speed models, TSB 17-035 extended the warranty on the ATF warmer due to internal leaks causing coolant and ATF to mix, leading to poor shifting and overheating. While not a direct cause of P0712's electrical fault, it's a critical transmission issue for these specific trims.

Mechanic-Grade Diagnostic Values

• TFT Sensor Signal Voltage (KOEO - Key On, Engine Off) — expected: Changes with temperature. Should not be static.. Failure: A static reading below 0.07 volts indicates a short circuit, triggering P0712.
• TFT Sensor Reference Voltage at Harness Connector — expected: Approximately 5.0 volts DC with the sensor disconnected and key on.. Failure: Significantly less than 5.0 volts points to a wiring issue or a problem with the PCM's 5V reference circuit.
• TFT Sensor Resistance — expected: Resistance changes with temperature. For example, a similar sensor shows ~2.5 kΩ at 20°C (68°F), with resistance decreasing as temperature rises.. Failure: An extremely low or near-zero resistance reading across the sensor terminals indicates an internal short. An open circuit (infinite resistance) would trigger P0713.

Scan Tool Commands That Help

• Honda Diagnostic System (HDS): Data List for A/T — To monitor the live voltage and temperature reading from the 'ATF Temperature Sensor' to confirm the fault. A reading below 0.07V is a key indicator.
• Honda Diagnostic System (HDS): Jumping the SCS (Service Check Switch) line — This is an advanced diagnostic step used before testing continuity at the PCM connector. It forces the system into a diagnostic mode.
• Honda Diagnostic System (HDS): Clear DTCs — After the repair is complete, the HDS is used to clear the fault code from the PCM's memory.

Wiring & Ground Locations

• PCM Connector B (51-Pin) — Located in the engine bay, connected to the Powertrain Control Module (PCM).. This connector contains the wire for the TFT sensor signal. Technicians disconnect this to test for a short to ground on the wire between the PCM and the transmission.
• Transmission Main Connector (Valve Body Connector) — The main external electrical connector on the transmission case that routes to the internal valve body and sensors.. This is the primary point for testing the sensor circuit without opening the transmission. A technician can check for reference voltage and test sensor resistance from this connector's pins.

Diagnostic Flowchart

Other Known Issues on This Vehicle

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

• Fuel Injector Failure 🔴 High — Can occur at relatively low mileage (as early as 25k miles), often causing misfires (P030x) and air-fuel ratio codes (P219A/B). (Ref: TSB 20-100 (extends warranty to 10 years/150k miles for this issue).)
• Auto Start/Stop System Failure 🟠 Medium — Common owner complaint where the engine fails to restart after stopping, or the system deactivates prematurely due to a weakening battery. Can sometimes be caused by water intrusion into the starter motor in cold climates. (Ref: TSB A23-008 / A23-009 address a no-restart condition.)
• Infotainment System Glitches (Blank Screen/Rebooting) 🟠 Medium — Widespread issue where the center display screen goes blank, freezes, or reboots randomly. Caused by a software issue in the gauge control module. (Ref: TSB 20-047 (Noncompliance Recall for a software update).)
• ZF 9-Speed Transmission Shift Quality 🟠 Medium → Shop Transmission Assembly — Prevalent on 2016-2020 Touring/Elite trims. Owners report harsh shifts, hesitation, and surging. Multiple software updates were released to improve behavior. (Ref: TSB 17-035 (ATF Warmer) and others address shift quality.)
• Direct Injection Carbon Buildup 🟡 Low — An inherent issue with the J35Y6 direct injection engine. Over time (typically 60k-100k miles), carbon can build up on intake valves, leading to rough idle and reduced performance.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For this repair, using a used part is generally not recommended. The Transmission Fluid Temperature (TFT) sensor is a relatively inexpensive electronic component that is critical for proper transmission function. The labor to access it by dropping the transmission pan is significant. The risk of a used sensor failing prematurely outweighs the small cost savings over a new part.

Donor-vehicle mileage cap: roughly under 50000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Verify the part number from the donor vehicle matches the required part for your 6-speed or 9-speed transmission.
• Inspect the connector pins for any signs of corrosion, damage, or oil contamination.
• If possible, test the resistance of the used sensor with a multimeter before purchase to ensure it's not shorted or open.

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

• Transmission Fluid Temperature Sensor: Given the high labor cost for replacement, using a Genuine Honda (or ZF for the 9-speed) part is the safest choice to ensure longevity and correct performance.
• Automatic Transmission Fluid (ATF): Always use the Honda-specified fluid (DW-1 for 6-speed, Type 3.1 for 9-speed). Using incorrect fluid can cause shifting problems and long-term damage.

Brands owners have reported issues with on this vehicle:

• Unnamed/no-brand sensors from online marketplaces. The quality control is often poor, and they may not have the correct resistance curve, leading to incorrect temperature readings even if they don't set a code.

Real Owner Stories

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

Related OBD-II Codes

• P0711 — Indicates a range/performance issue with the same Transmission Fluid Temperature Sensor 'A'. A failing sensor can trigger this code instead of, or along with, P0712 depending on the nature of the internal fault.
• P0713 — This is the opposite fault for the same circuit, indicating 'Sensor Circuit High Input'. P0712 is caused by a short to ground, while P0713 is caused by an open circuit. Both point to a problem with the TFT sensor or its wiring.
• P0700 — A generic Transmission Control System Malfunction code. It is set by the PCM to turn on the Check Engine Light when the Transmission Control Module (TCM) has stored a specific code like P0712.
• P0741 — Torque Converter Clutch Circuit Performance or Stuck Off. One of the symptoms of P0712 is improper torque converter clutch operation, as the TCM relies on an accurate temperature reading to control the TCC. A bad temperature signal can lead to this secondary code.
• P0300-P0306 — Cylinder Misfire codes. While not directly caused by the TFT sensor, these codes are common on the J35Y6 engine due to fuel injector issues (per TSB 20-100) and represent another frequent powertrain fault on this specific vehicle.

Frequently Asked Questions