What it means
Voltage on the outlet temperature sensor signal line of alternative fuel vaporizer C is below the expected window. Wire shorted to ground or sensor short.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The AFCM monitors the signal circuit for the outlet temperature sensor on vaporizer C. This circuit-low code sets when the signal voltage falls below its expected range, commonly because the signal wire is shorted to ground or the sensor is internally shorted.
Common causes
Most likely first.
- Signal wire shorted to ground
- Internal sensor short
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine or alternative-fuel system warning light
- Rough running or hesitation on alternative fuel
- Alternative-fuel operation may be limited
How to diagnose it
- Check freeze-frame and live AFCM data to confirm the vaporizer C outlet-temperature signal is reading abnormally low and note whether alternative-fuel operation was active.
- Inspect the sensor connector and harness for a pinched or rubbed-through signal wire, corrosion, moisture, or loose terminals.
- Use the wiring diagram to test the signal circuit for a short to ground and check the connector terminals for excessive resistance against the manufacturer's specification.
- With the sensor disconnected as directed by the vehicle service information, check whether the low signal remains to help distinguish a harness short from a sensor fault.
- If the wiring is sound, test the vaporizer C outlet-temperature sensor against the manufacturer's specification and replace it if internally shorted.
Common fixes
- Repair a vaporizer C sensor signal wire shorted to ground.
- Clean or replace corroded or damaged connector terminals.
- Replace the vaporizer C outlet-temperature sensor if it is internally shorted.
Can I keep driving?
If the engine runs smoothly on another available fuel, limit driving to what is needed and avoid alternative-fuel use if it causes hesitation. The AFCM may restrict that fuel because it cannot reliably control vaporization.
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.