What it means
Voltage on the outlet temperature sensor signal line of alternative fuel vaporizer C 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 AFCM monitors the signal circuit for the outlet temperature sensor on vaporizer C. This circuit-high code sets when signal voltage rises above its expected range, often because the signal wire is shorted to battery voltage or the sensor circuit is open.
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
- Review freeze-frame and live AFCM data to confirm the vaporizer C outlet-temperature signal is abnormally high or fixed at an implausible value.
- Inspect the sensor connector and harness for an open circuit, backed-out pins, corrosion, or a signal wire contacting a power feed.
- Use the wiring diagram to test the signal circuit for an open or short to B+ and check terminal contact against the manufacturer's specification.
- Follow service information to isolate the sensor from the harness, then see whether the high signal remains to narrow the fault to wiring or sensor.
- If the circuit is intact, test the vaporizer C outlet-temperature sensor against the manufacturer's specification and replace it if open.
Common fixes
- Repair an open or signal wire shorted to B+ in the vaporizer C sensor circuit.
- Restore proper terminal contact by repairing corroded, loose, or backed-out connector pins.
- Replace the vaporizer C outlet-temperature sensor if its element is open.
Can I keep driving?
If the engine runs normally on another available fuel, keep driving limited and avoid alternative-fuel operation if it causes hesitation. The AFCM may limit that fuel because it cannot trust vaporizer C's outlet temperature.
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.