What are the common causes of the P0713 code on a Subaru?

cause_transmission_fluid, cause_wiring_damage, cause_connector_corrosion

How much does it cost to fix the P0713 code?

The estimated repair cost for the P0713 code is $100 - $500. This includes parts and labor.

P0713Subaru WrxYears: 1996 - 2026

Transmission Fluid Temperature Sensor Circuit High Input

Reviewed by ASE Certified Technician

Is It Safe to Drive?Driving with a P0713 code can lead to unpredictable transmission behavior, including harsh or delayed shifts, incorrect torque converter lock-up, and potentially transmission overheating if the transmission control module (TCM) cannot accurately monitor fluid temperature. The TCM relies heavily on accurate TFT data for proper shift scheduling, line pressure control, and engagement of the torque converter clutch. Operating the transmission without this critical data can accelerate internal wear, reduce fuel economy, and potentially lead to costly transmission damage over time. It is strongly advised to have this issue diagnosed and repaired promptly to prevent further complications.

Advertisement Space (Leaderboard)

What does this mean?

Code P0713 indicates a problem with the transmission fluid temperature sensor.

Disclaimer: This diagnostic code is part of the standard OBD2 system and can apply to Subaru Wrx models manufactured from 1996 to 2026. However, please note that the presence of this specific code depends on your vehicle's exact engine configuration, options, and production year.

Advertisement (In-Article)

Common Causes

Low, dirty, or burnt transmission fluid

Damaged, chafed, or broken wiring harness

Corroded or loose electrical connector

Symptoms to Watch For

Check Engine Light is illuminated
Transmission overheating warning
Hard or harsh gear shifting

How to Diagnose

**Step 1: Initial Scan Tool Analysis and Visual Inspection.** Connect a professional-grade scan tool and retrieve all stored and pending Diagnostic Trouble Codes (DTCs). Specifically, monitor the Transmission Fluid Temperature (TFT) sensor live data. A P0713 "High Input" code typically indicates the Powertrain Control Module (PCM) is receiving a voltage signal that corresponds to an extremely low temperature (e.g., -40°F/-40°C) or an open circuit. This is often due to infinite resistance in the sensor or its circuit. Visually inspect the transmission wiring harness, paying close attention to the TFT sensor connector (if external) or the main transmission connector (if internal). Look for signs of corrosion, bent pins, chafing, cuts, or any physical damage that could lead to an open circuit or a short to voltage.

**Step 2: Electrical Circuit Testing at the Sensor Connector.** Locate the TFT sensor. On many modern transmissions, it's integrated into the valve body, lead frame, or an internal wiring harness assembly, requiring the transmission pan to be dropped for access. If accessible, disconnect the electrical connector from the TFT sensor. Using a Digital Multimeter (DMM), measure the resistance across the two terminals of the TFT sensor itself. A "High Input" code strongly suggests an open circuit within the sensor, so you should expect to read infinite resistance (OL) or a resistance value significantly higher than manufacturer specifications for ambient temperature. Next, with the ignition ON (engine OFF), measure the voltage at the harness connector going *to* the sensor. One wire should typically show a 5-volt reference signal from the PCM, and the other should be a ground. A constant 5V on the signal wire, or an absence of ground, could indicate an open circuit in the sensor or its ground path.

**Step 3: Wiring Integrity Check from Sensor to PCM.** With the TFT sensor connector disconnected and the PCM/TCM connector also disconnected (to prevent damage to the control module), perform continuity checks on the wiring harness. Use your DMM to check for continuity between the TFT sensor connector terminals and their corresponding terminals at the PCM/TCM connector. An open circuit on either the signal wire or the ground wire will cause a P0713. Additionally, check both wires for shorts to ground and shorts to voltage (e.g., 12V from another circuit). A short to voltage on the signal wire could also cause a "High Input" condition, as the PCM would interpret the higher voltage as an extremely low temperature or an out-of-range signal.

**Step 4: Advanced Sensor Verification (If Accessible and Wiring Passes).** If the TFT sensor is externally accessible and the wiring tests pass, you can further verify the sensor's function. Place the sensor in a controlled temperature environment (e.g., a cup of water with a thermometer) and measure its resistance at various temperatures. The resistance of a thermistor-type sensor (which TFT sensors typically are) should decrease as the temperature increases. Compare these readings to the manufacturer's resistance-temperature chart. If the resistance remains constant, is always extremely high, or does not change predictably with temperature, the sensor is faulty. If the sensor is internal and all wiring tests pass, the internal sensor itself is the most probable cause, necessitating transmission pan removal for replacement.

Common Solutions

**Replace the Transmission Fluid Temperature (TFT) Sensor:** This is the most frequent solution, especially if the sensor tests open circuit or out of specification. On many vehicles, this sensor is integrated into the internal transmission wiring harness, valve body, or lead frame assembly, requiring the transmission pan to be dropped for access and replacement.

**Repair or Replace Damaged Wiring or Connectors:** If diagnostic steps reveal an open circuit, a short to voltage, or corroded/damaged terminals within the wiring harness or connectors leading to the TFT sensor, these components must be meticulously repaired or replaced to restore proper circuit integrity.

**Address Powertrain/Transmission Control Module (PCM/TCM) Fault:** In rare instances, the PCM or TCM itself could be at fault, either failing to provide the correct 5-volt reference signal or misinterpreting the sensor's input. This should only be considered after thoroughly ruling out the sensor and all associated wiring as the cause.

Join the Discussion

Advertisement Space (Bottom Leaderboard)

AdvertisementSponsor/AdSense

Repair Estimate

$100 - $500

Parts$80 - $650

Labor$180 - $900

DIY Difficulty

Hard

Other Popular Subaru Codes

P0116 P0121 P0127

Transmission Fluid Temperature Sensor Circuit High Input

Reviewed by ASE Certified Technician

What does this mean?

Code P0713 indicates a problem with the transmission fluid temperature sensor.

How to Diagnose

Common Solutions

What does this mean?

Common Causes

Symptoms to Watch For

How to Diagnose

Common Solutions

Join the Discussion

Repair Estimate

DIY Difficulty

Other Popular Subaru Codes

Scanning Engine...

What does this mean?

Common Causes

Symptoms to Watch For

How to Diagnose

Common Solutions

Join the Discussion

Repair Estimate

DIY Difficulty

Other Popular Subaru Codes