What it means
Voltage on the outlet temperature sensor signal line of alternative fuel vaporizer B 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 outlet-temperature sensor on alternative fuel vaporizer B sends a signal to the AFCM so it can control fuel vaporization. This code sets when the signal voltage falls below the expected range, commonly because the signal is shorted to ground or the sensor itself 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
- Use a scan tool to capture freeze-frame data and check vaporizer B outlet-temperature data and related alternative-fuel circuit codes.
- Inspect vaporizer B's sensor connector and harness for chafing, crushed insulation, corrosion, or a signal wire touching ground.
- With the manufacturer's wiring diagram, check the vaporizer B signal circuit for a short to ground and inspect connector terminals for corrosion or poor contact.
- Test the sensor and its circuit separately as specified by the manufacturer to distinguish an internally shorted sensor from a harness fault.
- Repair the confirmed wiring or connector fault, or replace the sensor if it fails the manufacturer's test, then confirm the signal is plausible.
Common fixes
- Clean and reseat the vaporizer B sensor connector if its terminals are dirty or loose.
- Repair the vaporizer B signal wire where it is shorted to ground or damaged.
- Replace the vaporizer B outlet-temperature sensor if it is internally shorted.
Can I keep driving?
If the vehicle runs normally on conventional fuel, limit driving to that mode if available and avoid alternative-fuel use when it causes hesitation. The AFCM may restrict alternative-fuel operation, and poor vaporization control can worsen running and emissions.
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.