What it means
The ECM detects a circuit intermittent/erratic fault on the drive motor a temperature sensor b circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Drive Motor A temperature sensor B reports temperature for motor protection and control. This code sets when the module sees the sensor B signal fluctuate erratically or drop in and out, often because of an intermittent connector, wiring, or ground reference.
Common causes
Most likely first.
- Sensor connector not seated
- Noisy ground reference
- Connector with intermittent contact under vibration
Symptoms
- EV/hybrid system warning light on
- Reduced motor power or torque
- Possible limp mode or vehicle shutdown
How to diagnose it
- Review freeze-frame records and live data for Drive Motor A temperature sensor B to see whether the reading jumps, drops out, or recovers as the fault occurs.
- Inspect sensor B's connector for an incomplete latch, loose terminals, corrosion, or contamination, and check the nearby harness for chafing.
- With the vehicle secured and using the manufacturer's safe procedure, gently move the accessible sensor B harness while monitoring the live reading for dropouts.
- Check the sensor B ground reference and circuit connections for intermittent contact using the manufacturer's diagnostic procedure.
- Repair the loose or unstable connection, then clear the code and confirm the reading remains steady during operation.
Common fixes
- Fully seat and latch the sensor B connector.
- Clean or repair loose, corroded, or damaged sensor B terminals.
- Repair wiring or ground-reference connections that fail intermittently under movement.
- Replace sensor B if its output remains erratic after circuit connections are sound.
Can I keep driving?
Avoid high-load driving because an intermittent sensor B signal can prompt reduced torque or limp mode without warning. If power cuts significantly or a shutdown warning appears, stop safely and arrange service.
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.