What it means
The ECM/PCM produces a torque-management output signal for downstream consumers (TCM during shifts, hybrid module, transfer case) and detects a fault on this output — open, short, or feedback voltage outside expected range. Without it, downstream modules cannot synchronise their behaviour with the engine.
At a glance
- Usually lights the check-engine light
How it works
The engine or powertrain control module sends a torque-management request to other systems so they can coordinate actions such as transmission shifts. It monitors the output circuit and sets this code when the signal is open, shorted, or has feedback outside the expected range, including when a downstream device does not load the line as expected.
Common causes
Most likely first.
- Open or shorted output line
- Downstream consumer not loading the line
Symptoms
- Check-engine light may come on
- Harsh or delayed transmission shifts may occur
- Reduced engine power or drivability changes may occur
How to diagnose it
- Review freeze-frame data and related transmission or powertrain codes to identify which operating condition accompanied the output fault.
- Use a scan tool to check torque-management request data and note any shift or powertrain events that coincide with the fault.
- Inspect the output wire and connectors between the ECM or PCM and downstream modules for loose pins, corrosion, chafing, or heat damage.
- With power isolated as specified by the manufacturer, test the output circuit for continuity and shorts, and compare its signal and load behavior with the manufacturer's specification.
- If wiring and connected loads test correctly, check the relevant downstream module and ECM or PCM output using the manufacturer's diagnostic procedure.
Common fixes
- Secure a loose torque-management output connector or repair damaged terminals.
- Repair an open or short in the output wire.
- Repair a poor connection at the downstream module that prevents it from loading the signal.
- Replace a confirmed faulty downstream module or ECM/PCM only after circuit checks identify it as the cause.
Can I keep driving?
You may be able to drive, but shifts can become harsh or delayed and engine power may change. Avoid heavy acceleration or towing; stop if power loss or transmission behavior makes the vehicle unsafe to control.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.