What it means
Intermittent signal from alt fuel tank temp sensor. 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
- Affects emissions; the car can fail an emissions test
How it works
The alternative-fuel tank temperature sensor reports tank temperature through a signal circuit monitored by the control module. P01AE indicates that this signal intermittently fluctuates or drops out, often when a loose connection or vibrating harness interrupts contact.
Common causes
Most likely first.
- Connector loose or corroded
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
Symptoms
- Check-engine light may come on intermittently
- Alternative-fuel tank temperature reading may fluctuate or drop out
- Alternative-fuel system warning may appear
How to diagnose it
- Review freeze-frame data and monitor live tank temperature to confirm whether the reading drops out or jumps while the code is active.
- Inspect the sensor connector for a loose fit, corrosion, moisture, or terminals that may lose contact under vibration.
- Gently wiggle the connector and harness while watching live data to locate a movement-sensitive fault.
- Check the harness routing for contact with vibrating parts and inspect the area for chafed insulation.
- Test circuit continuity and sensor connections while flexing the suspect section, following the manufacturer's procedure.
Common fixes
- Secure the loose tank temperature sensor connector.
- Clean or replace connector terminals that are corroded or intermittently contacting.
- Repair chafed wiring and secure the harness away from vibration.
- Replace the temperature sensor if its signal remains intermittent with sound wiring.
Can I keep driving?
If the vehicle runs normally, limit driving and watch for alternative-fuel warnings or changes in operation. Stop if the engine runs poorly or a fuel-system warning appears, since the temperature signal can drop out again.
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.