Damaged or corroded wiring in the engine torque control signal 2 circuit, especially near connectors or where the harness bends; Faulty transmission control module (TCM) or engine control module (ECM) connector pins or internal circuitry; Open or shorted signal wire between the ECM and TCM; Failed sensor or actuator that provides the torque control signal, such as a faulty throttle position sensor or accelerator pedal position sensor; Poor ground connection shared by the ECM or TCM; Aftermarket electronic modifications or poor previous repairs tapping into the circuit; Internal failure of the TCM or ECM (less common but possible)

DTC codes / Subaru codes / P1712

P1712 · SubaruEngine Torque Control Signal 2 Circuit Malfunction

Q: What does code P1712 mean?

Engine Torque Control Signal 2 Circuit Malfunction. P1712 on a Subaru means the engine control module (ECM) has detected an electrical fault in the circuit that carries the second engine torque control signal, which is used to coordinate torque reduction requests between the ECM and the transmission control module (TCM). The ECM monitors the signal line for expected voltage or current behavior and sets this code when the signal is out of range, intermittent, or missing entirely.

P1712 on a Subaru means the engine control module (ECM) has detected an electrical fault in the circuit that carries the second engine torque control signal, which is used to coordinate torque reduction requests between the ECM and the transmission control module (TCM). The ECM monitors the signal line for expected voltage or current behavior and sets this code when the signal is out of range, intermittent, or missing entirely.

SystemPowertrain

Code typeSubaru specific

SeverityMedium

Fix difficultyProfessional

AreaTransmission

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Harsh or delayed automatic transmission shifts as torque reduction during shifts is compromised
Slight hesitation or stumble during acceleration when the ECM requests torque reduction
Reduced engine power or limp-home mode in some cases
Poor fuel economy or altered throttle response
In rare cases, the transmission may default to a fixed shift pattern

Common causes, most likely first

Damaged or corroded wiring in the engine torque control signal 2 circuit, especially near connectors or where the harness bends
Faulty transmission control module (TCM) or engine control module (ECM) connector pins or internal circuitry
Open or shorted signal wire between the ECM and TCM
Failed sensor or actuator that provides the torque control signal, such as a faulty throttle position sensor or accelerator pedal position sensor
Poor ground connection shared by the ECM or TCM
Aftermarket electronic modifications or poor previous repairs tapping into the circuit
Internal failure of the TCM or ECM (less common but possible)

How to diagnose and fix it

Connect a scan tool and record all stored codes and freeze-frame data to confirm P1712 is active and not a ghost code from a low battery
Visually inspect the engine wiring harness and connectors between the ECM and TCM for chafing, corrosion, or loose pins
Perform a wiggle test on the harness while monitoring the torque control signal 2 parameter on the scan tool to catch intermittent faults
Measure resistance and voltage on the signal circuit according to the factory service information to check for opens, shorts to ground, or shorts to power
Check and clean the ECM and TCM ground connections, then retest
If the circuit tests good, substitute a known-good TCM or ECM only after confirming all other possibilities, as these modules are expensive
Clear the code and perform a relearn or adaptation drive cycle as specified by Subaru, then verify the code does not return

What Subaru techs check before replacing modules

A weak or failing battery often causes this code on Subarus because the ECM and TCM are sensitive to voltage drops during cranking, so load-test the battery before anything else.
The torque control signal 2 circuit often shares a connector with other signals, so a single bent pin can set multiple codes; always inspect the whole connector, not just the wire for this code.
Aftermarket remote starters or piggyback tuners that splice into the CAN bus or throttle wiring frequently disturb this signal and set P1712 without any hard failure.
The code can be set by a faulty brake pedal position switch on some Subaru models because the ECM uses brake status to calculate torque requests, so check that switch if the circuit tests fine.
Do not replace the TCM or ECM based solely on P1712; in most cases the fault lies in the harness or a connector, and module replacement without fixing the root cause will not solve the problem.

Can I keep driving with P1712?

You can usually drive the car short distances to a repair shop, but avoid heavy acceleration or towing because the compromised torque control can cause harsh shifts and may lead to transmission damage over time. If the car enters limp mode or shifts erratically, stop driving and have it towed.

Tools that help

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Guidance is general and written for Subaru vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.