What it means
Voltage on the outlet temperature sensor signal line of alternative fuel vaporizer B is above the expected window. Wire shorted to B+ or sensor open.
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 reports fuel temperature to the AFCM for vaporization control. This code sets when the signal voltage is above the expected range, which can result from a signal wire shorted to battery voltage or an open sensor circuit.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open temperature sensor
- 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
- Record freeze-frame data and check whether vaporizer B outlet-temperature data is fixed, implausibly high, or absent, along with related circuit codes.
- Inspect vaporizer B's sensor connector and wiring for a loose terminal, broken conductor, damaged insulation, or contact with a power feed.
- Using the manufacturer's wiring diagram, check the signal circuit for an open or short to battery voltage and inspect terminals for corrosion or poor contact.
- Test the vaporizer B sensor and circuit separately using the manufacturer's procedure to identify an open sensor or a harness fault.
- Repair the confirmed circuit fault or replace the failed sensor, then verify that live temperature data responds plausibly.
Common fixes
- Reseat or clean the vaporizer B sensor connector if its terminals have poor contact.
- Repair the vaporizer B signal wire if it is open or shorted to battery voltage.
- Replace the vaporizer B outlet-temperature sensor if it has an open circuit.
Can I keep driving?
If the vehicle runs normally on conventional fuel, use that mode if available and avoid alternative-fuel operation when it causes hesitation. Unreliable vaporizer B temperature feedback can lead the AFCM to limit alternative-fuel operation and can increase 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.