What it means
ECU lost CAN communication with the pedestrian alert (acoustic vehicle alerting) module — required by law on EVs/hybrids at low speed.
At a glance
- Usually lights the warning light of the system that lost communication
How it works
The pedestrian alert control module operates the external sound alert used on many electric and hybrid vehicles at low speeds. U013F sets when expected network messages from that module are missing, so the alert may not sound when required.
Common causes
Most likely first.
- Module unpowered
- Gateway module routing CAN messages incorrectly
- CAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
How to diagnose it
- Scan all modules and review freeze-frame data for U013F and any low-voltage or network communication codes.
- Check battery and charging-system condition, since low voltage can interrupt communication with the pedestrian alert module.
- With the vehicle safely parked and following the owner's instructions, check for an alert-system warning and inspect the module connector and visible wiring for damage, looseness, or corrosion.
- Use vehicle service information to check the module's power and ground circuits against the manufacturer's specification.
- Test its network wiring and any gateway path for opens, shorts, or poor connections using the manufacturer's procedure.
- If power, ground, and network wiring are sound, check whether the module responds to a scan tool before considering replacement or configuration.
Common fixes
- Restore battery or charging-system performance if voltage is low.
- Secure or repair a loose, corroded, or damaged pedestrian alert module connector.
- Repair damaged network wiring or gateway connections to the module.
- Repair the module's power or ground supply.
- Replace and configure the pedestrian alert control module if it remains unresponsive with sound circuits.
Can I keep driving?
Arrange prompt repair and drive slowly and cautiously around pedestrians until the alert is confirmed to work. A silent low-speed alert can make the vehicle harder for people nearby to hear.
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.