What it means
Same as P0668 on internal sensor B. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
How it works
The control module monitors internal temperature sensor B through a dedicated signal circuit. P06AD sets when that circuit's signal is lower than expected, commonly because the sensor is internally shorted or the wiring is contacting ground; the affected module functions vary by vehicle.
Common causes
Most likely first.
- Sensor internal short
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
How to diagnose it
- Scan all modules, save freeze-frame data, and note whether sensor B circuit-low and communication or powertrain faults appeared together.
- Check live data for internal temperature sensor B and see whether its reading is abnormally low or changes when the harness is gently moved.
- Inspect the module connector and sensor B harness for chafing, moisture, corrosion, pushed-back pins, or a short to ground.
- Use the wiring diagram to test the sensor B signal circuit for shorts to ground and check connector contact and continuity.
- If the external circuit is sound, test the internal sensor B and module input against the manufacturer's specification.
Common fixes
- Clean and secure corroded or loose connector terminals.
- Repair chafed wiring or a sensor B signal wire shorted to ground.
- Replace the internal temperature sensor B if it is shorted.
- Repair or replace the control module if its sensor input fails testing, then perform any required relearn.
Can I keep driving?
Because this fault can accompany limp mode, multiple module faults, or a no-start, avoid long trips and do not rely on the vehicle if it enters reduced-power operation. If it stalls, will not restart, or engine control becomes unpredictable, stop driving and arrange recovery.
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.