What it means
The BMS detects a circuit high fault on voltage sense channel T of the high-voltage battery. Cell-group voltage measurement is unreliable on this channel.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The BMS measures cell-group voltage through separate sense paths, including channel T. This code sets when the channel T signal is above its expected range, making that cell-group measurement unreliable and potentially causing the system to restrict battery operation.
Common causes
Most likely first.
- Sense wire shorted to higher voltage
- Reference regulator overvoltage
- Connector pins corroded - high contact resistance
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Record freeze-frame data and compare live channel T voltage with adjacent cell-group readings to see whether the high signal is persistent or occurred during a particular operating condition.
- With the vehicle safely powered down under the manufacturer's high-voltage procedure, inspect channel T's wiring and connector for damage, contamination, or contact with a higher-voltage conductor.
- Check channel T connector pins for corrosion, looseness, or poor contact, which can distort the signal even when the wiring appears intact.
- Have a qualified hybrid technician test the channel T sense wire for shorts to higher voltage and verify its reference supply against the manufacturer's specification.
- If wiring and reference checks pass, test the battery monitoring module's channel T input according to the manufacturer's procedure.
Common fixes
- Secure the channel T harness if it is contacting another conductor.
- Clean or repair corroded or loose channel T connector pins.
- Repair or replace channel T wiring found shorted to a higher-voltage circuit.
- Repair the reference regulator or replace the battery monitoring module only if testing identifies it as the source of the excessive signal.
Can I keep driving?
Limit driving, especially hard acceleration, and avoid relying on normal charging or electric range until the fault is diagnosed; the vehicle may reduce power or refuse charging. Stop if a battery safety warning appears or the vehicle behaves unpredictably.
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.